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.

The primary concern of this paper is a single-blade air torque position damper used for the indirect measurement of volumetric air-flow rates by measuring the moment of airstream force exerted on the blade and the damper position. The purpose of the paper is to analyze the accuracy of the air velocity measurements and the adequacy of the damper mathematical model on the basis of the blade profile and the damper location in a duct system. The analysis was performed on the basis of the experimentally obtained results. Four different blade profiles (flat, V-groove, symmetrical airfoil, and non-symmetrical airfoil blades) were taken into account, as well as three different damper locations in the duct system (at the duct entrance, within the duct, and at the duct exit). Two blade orientations at the duct entrance were examined relative to the direction of air-flow (with front and rear mounting flanges). It was determined that the blade profile and particularly the damper location in the duct system affect the measurement accuracy and the adequacy of the damper mathematical model provided the blade angle of attack is less than or equal to 30?, i. e. within the range of a more open damper.

This paper is focused on the mathematical model of the Air Torque Position dampers. The mathematical model establishes a link between the velocity of air in front of the damper, position of the damper blade and the moment acting on the blade caused by the air flow. This research aims to experimentally verify the mathematical model for the damper type with non-cascading blades. Four different types of dampers with non-cascading blades were considered: single blade dampers, dampers with two cross-blades, dampers with two parallel blades and dampers with two blades of which one is a fixed blade in the horizontal position. The case of a damper with a straight pipeline positioned in front of and behind the damper was taken in consideration. Calibration and verification of the mathematical model was conducted experimentally. The experiment was conducted on the laboratory facility for testing dampers used for regulation of the air flow rate in heating, ventilation and air conditioning systems. The design and setup of the laboratory facility, as well as construction, adjustment and calibration of the laboratory damper are presented in this paper. The mathematical model was calibrated by using one set of data, while the verification of the mathematical model was conducted by using the second set of data. The mathematical model was successfully validated and it can be used for accurate measurement of the air velocity on dampers with non-cascading blades under different operating conditions.

This paper contains an overview of fabrication methods used for the construction of different microfluidic devices, along with some example applications. All the different procedures, methods, and their respective variants are collectively referred to as microfabrication methods. Microfabrication plays a crucial role in microfluidics, as the fabrication method directly influences the potential application of a device. The overview of fabrication methods can be categorized based on the mechanical properties of the materials used. In this context, the primary mechanical property considered is material rigidity, classifying materials into hard, plastic and soft categories. Other mechanical properties affect the possibility of use in extreme temperatures (hot or cold), reactive or neutral environments, and one of the most critical characteristics of microfluidic devices - biocompatibility. Some of the most widely used methods discussed in this paper include photolithography and its variants, etching technique for silicone and glass, PDMS molding, micro milling, and 3D printing. Additionally, paper-based microfluidics is highlighted as an excellent example of biocompatible microfluidic devices applied in medical applications.