Table of Contents



    • Estimation of modal split parameters – a case study

      pg(s) 51-53

      Choosing a mode or type of transportation is certainly one of the most important steps in a classic transportation model, given that it has a significant impact on the traffic planning and transport policy of a city. The choice of transport mode (e.g. passenger car, public transport, bicycle, walking) depends on the availability of transport modes and the generalized cost of transportation by transport mode from origin to destination. The choice of mode of transportation is also significantly influenced by the trip purpose. The most commonly used model for determining the modal split is the logit model. Parameters of utiliy function for each mode were estimated based on a household travel survey in Slavonski Brod, Croatia using the Biogeme program. The generalized cost and impedance towards using each transport mode is expressed by the utility function. This paper presents a methodology for determining the utility function for each transport mode using the Biogeme program.

    • The future of moto auto world

      pg(s) 54-55

      The new decade symbolically heralds the year of innovations and advancements in automobile sector. Dutch company “Lightyear” has announced that the first “long-range” solar-powered car arrives in 2021. “Lightyear One” will be charged on the household socket, and with a charged battery will be able to cover a distance of 725 kilometars.
      At the fair in Las Vegas, a special place was given to electric “Mustang“ with 900 hp. Among the many versions of “Ford Mustang“, for this model six-speed manual transmission was designed and the driver has at disposal three regimes, and the system is controlled by a large central touch screen.
      The new European drone regulation, in effect July 1st 2020 will require new compliance and registrations by their users. Unfortunately, during 2019, the public learned that “Audi” is withdrawing 138.000 A3 models of the following class, because their airbag does not open due to a malfunction, (models were manufactured between years 2015 and 2019) and these are: 2015-2019 A3 Sedan, 2015 – 2019 A3 Cabriolet (convertible), 2016-2018 A3 E-Tron (plug-in hybrid), 2017-2019 RS3 (based on the A3), 2015-2016 S3 Sedan (based on the A3).
      At the end of 2019, the merger of “Fiat Craisler” and “Peugeot – Citroen”, the two auto giants on the basis of 50:50 and production of 8.7 million cars a year were announced. More recent information comes with the knowledge that these car companies which are in negotiations will sign the merger agreement, which would create the fourth largest car producer in the world. In Serbia there is shortage of about 10.000 drivers and from 80.000 active, already about 10.000 so far took the card and certificate for driving motor vehicles through Europe. Drivers are still in the category of the most wanted professions. In Belgrade City Transportation
      Enterprise is planning to hire 110 new drivers for the largest city carrier. Interesting is also the phenomenon of electric scooters that became almost mandatory means of transport in cities throughout the world. These vehicles necessarily need legal restrictions, and it is interesting that Germany already limits the use of electric scooters.

    • Development of railway junction Sofia based of project for reconstruction and modernization

      pg(s) 56-59

      From 2013 to 2015, an “Instrument for the preparation of railway projects on the trans-European transport network” is implemented. The project is funded under Priority Axis 5 “Technical Assistance” of the Operational Program Transport 2007-2014. A total of 11 project preparation lots are being developed. The most important are the projects for the development of Sofia railway junction, Burgas railway junction, reconstruction and modernization of existing stations, preparation of detailed development plans and technical design for new stops and buildings, assessment and verification of compliance with the requirements for interoperability. For the technical design phase, the following projects are being developed: “Modernization of the Sofia – Dragoman railway line”, “Modernization of the Sofia – Pernik – Radomir railway line,” Development of the Sofia railway junction “and” Development of the Burgas railway junction “. Field surveys are conducted to search for archaeological sites within the scope of the projects. The article examines projects in terms of the need for exceptions to Ordinance 55.

    • An empirical investigation of hull and propeller vessel performance under the ISO standard 19030

      pg(s) 60-63

      Inefficient energy utilization is intolerable amongst ship operators and regulatory authorities especially in the current era. When the condition of a ship’s hull and or propeller-s degrades, in order to maintain speed, there is a need for more power thus more fuel. A byproduct of the increased fuel consumption is increased Green House Gas emissions that are strictly regulated by international authorities. In the present paper the Hull and Propeller performance will be assessed in terms of fuel consumption reserves and CO2 emissions based on the required levels environmental footprint as indicated by the ISO Standard 19030 created by the International Maritime Organization


    • Energy and exergy analysis of deaerator from combined-cycle power plant

      pg(s) 64-67

      Energy and exergy analysis of deaerator from combined-cycle power plant is presented in this paper. The deaerator is analyzed in three operating regimes and in various ambient conditions. The lowest deaerator energy loss of 525.60 kW and the highest energy efficiency of 78.21 % are obtained for the lowest water temperature at the deaerator outlet – in the same operating regime is obtained the lowest deaerator exergy efficiency. Decrease in the ambient temperature resulted simultaneously with an increase in deaerator exergy destruction and with increase in exergy efficiency. Deaerator exergy efficiency in each operating regime and for each observed ambient temperature significantly varies (from 13.82 % to 45.94 %). From the efficiency aspect, deaerator energy and exergy analysis show diametrically opposed results in two observed operating regimes.

    • The possibility and analysis of using gas as an alternative fuel in the diesel engine

      pg(s) 68-70

      the article considers the possibilities of diesel engine operation on gaseous fuels, as well as their advantages over standard engines. The focus is on the possibility of running effectively the gas-diesel cycle so that it is brought to the processes occurring in the engine with forced ignition as close as possible. The article also discusses the issues related to optimization of the processes occurring in the gasdiesel engine, which will bring the gas-diesel cycle close to the petrol-running cycle. There are also identified ways to improve the economic and environmental performance of the diesel engine

    • Indexes of gas engine converted from a tractor diesel

      pg(s) 71-73

      The experience of foreign companies on conversion of diesel vehicles for natural gas operation was analyzed. The results of computer simulations of the gas engine and diesel duty cycle were presented. The features of the gas engine power system converted from the D-243 tractor diesel are shown. The efficiency of the entire range of speed and load modes of a gas engine converted from D-243 diesel to run on natural gas has been experimentally confirmed by reducing the compression ratio from 16 to 12 and equipping it with a gas supply system and ignition system. Its effective power is close to that of a base diesel engine, equivalent to a specific fuel efficiency of up to 25% higher than that of a diesel engine. There is no carbon black in the exhaust gas of the gas engine. The emissions of certain harmful substances in some modes of operation of the gas engine are higher than that of the diesel, but the total toxicity of the exhaust gases resulting from carbon monoxide in the gas engine is 1.96 times lower than that of the diesel.