There are very few issues that are as important to our collective future as energy. Like everyone else, Serbia has its stake in reducing energy price, enhancing the security of energy supply, and ...reducing emissions, including greenhouse gas (GHG) emissions associated with fossil fuels. In the years to come Serbian economy is expected to grow and industry to search and explore the potential of using cleaner alternative fuels. There is a lot that could be done to conserve energy and to reduce environmental footprint. But the most important thing that could be done to enable Serbian industry to reduce emissions is the implementation of a modernized Power Generation system. At the same time the reality can?t be neither sugarcoated nor ignored and alternatives to fossil fuel will succeed only if they are economically feasible for suppliers and users alike. New technologies currently under development should be considered to allow Serbia the use of energy resources in a more efficient ways and with better protection of the environment. If successfully deployed, the development of alternative, renewable fuels will allow Serbian energy sector to effectively decouple its growth from GHG emissions. This paper explore opportunities and the potential of alternative fuels for increasing competition in energy supply, for reducing emissions and in Serbia while decreasing dependence on imported energy.
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Phonon thermal conductivity of graphene Jaćimovski, Stevo K.; Bukurov, Maša; Šetrajčić, Jovan P. ...
Superlattices and microstructures,
12/2015, Volume:
88
Journal Article
The study of graphene thermal conductivity is of great importance, as its anomalous thermal and electrical conductivities (the largest among the all known materials so far) provide very good ...perspectives for graphene-based nanoelectronics devices. Thermal conductivity of graphene is phonon-based, since its electronic-based thermal conductivity represents less than 1% of the total thermal conductivity at room temperature. For the consideration of the thermal conductivity of graphene the Boltzmann equation in the approximation of relaxation time is used. The relaxation time is determined, with three mechanisms of phonon scattering accounted simultaneously: at defects, at borders, and on phonons. Temperature dependence of thermal conductivity is determined numerically in the range from 15 K to 400 K. The results obtained are in accordance with some other available results found in literature, obtained either experimentally or by numerical calculations.
•Thermal conductivity of graphene is calculated by using Boltzmann equation.•Approximation of relaxation time with three mechanisms of phonon scattering is used.•Wide-range temperature dependence calculations of thermal conductivity are done.•The results are basically in accordance with other theoretical and experimental data.
The aim of this study was to examine the effects of osmotic pretreatment on some physical properties of quinces. Osmotic drying was performed in a saccharose and water solution. The temperatures of ...osmotic solution were 40 °C and 60 °C, and the initial concentrations were 50 °Bx and 65 °Bx. All four combinations were used in the experiment. High values of the total colour change DE* were recorded following the treatment of quince samples with the osmotic solution of 65 °Bx. Lower values of the total colour change were recorded in the same samples after convective drying. Slighter changes in colour after convective drying were caused by a greater amount of solute retained on the surface of the fruit, forming barriers between the fruit tissue and the surrounding air. Mechanical properties of quinces during osmotic drying expressed by the force ratio f = (F0 – Fi)/F0 and modulus of elasticity showed dependence on the temperature of the osmotic solution. At 60 °C, the osmotic solution caused softening of the quince tissue. Thermal softening had a positive influence on the naturally hard quince tissue. The results of the study demonstrate positive effects of osmotic drying on physical properties and quality of dried quinces.
Mergers and Acquisitions (M&A) have a long history but unfortunately a very short lifespan. The high degree of their failure opens up old issues and requires new answers. This paper presents an ...original view on Mergers and Acquisitions applying the scientific method of analogy with soap bubbles, with a special attention devoted to the 'hard' and 'soft' indicators of M&A success. The aim of this paper is to highlight the particular significance of hardly measurable, so-called 'soft' elements of (un)success in M&A and through the analogy with soap bubbles to clarify the reasons of M&A failures. In order to verify the similarities of soap bubbles with real business situations, authors provided relevant analogies strengthened with an analysis of short case studies. Based on the conclusions, decision-makers in this business environment will be able to implement such business strategies in order to create more effective business alliance which will last longer.
Being aware of the waterway capacity, as a substantial characteristic of each traffic way, has a great importance to authorities that perform control and regulation of the vessel traffic. In specific ...real conditions and situations, for the purpose of the vessel traffic control, it is necessary to know specified limits of traffic density, which depends on corresponding parameters of observed system (ship lock zone). The vessel traffic control in the zone of ship lock is a complex system that is made of numerous subsystems. Determination of subsystems and their external and internal connections is conducted according to analysis of a real system. Simulation model is developed according to the analyzed model of vessel traffic process. Developed simulation model contain data on vessels which have passed through the observed system in defined time interval. Also, it contains statistic data on number of vessels and delays due to waiting queues for locking. An application of this model is possible in all cases of the waterway capacity determination by varying numerical data. Obtained results may be used as a planning and decision-making support in the process of the vessel traffic control in the zone of ship lock with two parallel chambers. PUBLICATION ABSTRACT
This paper deals with filter nozzles which are used for water treatment. They are applied in many sectors including drinking water, water demineralization process, urban and industrial waste water ...treatment, filtration of river or well water for irrigation, water for swimming pools, etc. The filter nozzles are made from the thermoplastic material, with different number and widths of gaps at the head of the nozzles. It is necessary to determine performance curve of filter nozzle before it is installed. The performance curve actually represents the nozzle water gauge head as a function of flow rate. This performance curve has been traditionally determined by measuring of hydrostatic pressure above the nozzle with level meters (graduated scale, ultrasound, capacity etc.). In order to measure a couple of meters water gauge head, a reservoir is necessary. This research is aimed to examine possibility to apply the installation with column and manometer instead of the reservoir, in order to determine filter nozzle performance curve. The water gauge head is measured by manometer and flow rate through the filter nozzle by mass method. Authors are of the opinion that installation with column and manometer could be successfully applied to determine filter nozzle performance curve. In comparison with the reservoir, the installation with column and manometer is more compact and comfortable. PUBLICATION ABSTRACT
Spajanja i preuzimanja (M&A - Mergers and Acquisitions) imaju dugu povijest, ali nažalost vrlo kratak životni vijek. Visok stupanj njihovog neuspjeha otvara stara pitanja i zahtijeva nove odgovore. ...Ovaj rad predstavlja izvorni pogled na spajanja i preuzimanja primjenom znanstvene metode analogije s mjehurima od sapunice, gdje je posebna pažnja posvećena "tvrdim" i "mekim" pokazateljima M&A uspjeha. Cilj ovog rada je ukazati na određeni značaj jedva mjerljivih, takozvanih "mekih" elemenata (ne)uspjeha u M&A, a kroz analogije sa mjehurićima od sapunice pojasniti razloge neuspjeha spajanja i preuzimanja. Kako bi potvrdili sličnosti mjehurova od sapunice s realnim poslovnim situacijama, autori su pružili relevantne analogije ojačane analizom kratkih studija slučaja. Na temelju zaključaka, donositelji odluka u ovakvim poslovnim uvjetima će moći provoditi takve poslovne strategije koje će stvarati učinkovitije poslovne saveze koji će trajati duže.
According to the Serbian energy strategy implementation in the field of renewable energy sources for the period 2006-2010 and its implementation until 2015, will be created conditions for new jobs ...what requires big and fast changes and actions at the local level with a help of authorities at national and local level. Project Ener-Supply should assist the local authorities in these actions, particularly in relation to the utilization of renewable energy sources (RES) and the implementation of energy efficiency (EE) measures. The project Ener-Supply is financed by the South-East Europe Transnational Cooperation Programme of European Union. The target of the project in Serbia is AP Vojvodina. Here is presented an analysis of the state of the art and action plan for RES map building in Vojvodina and legal framework and strategies at national and local level as well as available RES studies. Also is presented planned implementation of RES projects with SWOT analyses.
Sucrose solution viscosity determination on evaporator by Coriolis flow meter Bikić, S., Faculty of Technical Sciences, Novi Sad (Serbia); Bukurov, M., Faculty of Technical Sciences, Novi Sad (Serbia); Babić, M., Faculty of Agriculture, Novi Sad (Serbia) ...
Journal on Processing and Energy in Agriculture,
(2011), Volume:
15, Issue:
4
Journal Article
Open access
The scope of this paper is the determination of viscosity of sucrose solutions using the Coriolis flow meter. Previous research showed that the Coriolis flow meter can be successfully applied to ...determine the viscosity of water, where instead of the straight pipeline section pressure drop is measured on the Coriolis tube. In this paper a technical solution applied to a sucrose solution is proposed. The goal of this research is to consider the possibility of applying this proposed technical solution to reliable sucrose solution viscosity measurement during the evaporation process in the evaporator. Experimental studies were conducted with the evaporator developed at the Laboratory of Bioengineering, the Faculty of Agriculture in Novi Sad (Serbia). Two sets of measured data were used for data processing. One set of data was used for mathematical modeling, and the other was used for verification of the mathematical model. It has been proven that if the temperature of the solution t, concentrations C and hydraulic parameter deltap/Q of the system are taken into account, the proposed concept of the measuring system can reliably be used for continuous measurement of viscosity of a sucrose solution. This is true even if conditions for the Hagen–Poiseuille flow are violated. This proposed solution for measuring reduces the number of sensors required for viscosity measurement. This increases compactness and simplifies construction of the evaporator in which the measuring system is built in. Since the Coriolis meter measures the density of the fluid, the proposed technical solution makes it possible to determine the dynamic and kinematic viscosity of the sucrose solution in the process of evaporation.
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