THE HYDROLOGICAL AND ENVIRONMENTAL ASPECT OF LOW FLOW ASSESSMENT IN UNGAUGED BASINS – A CASE STUDY IN THE JUŽNA MORAVA RIVER BASIN

Eighteen low flow indicators are considered in the research of sixteen hydrological stations in the Južna Morava river basin. The indicators are estimated by statistical analysis and grouped as hydrological and environmental indicators. A cross-correlation between all indicators is assessed. Environmental flows at hydrologic stations are obtained by the GEP method. The environmental low flow indicators are transferred to two small ungauged basins by regression with physiographic characteristics. The adjustment of environmental flows at ungauged basins is performed according to the locations of the donor stations in the hydrogeological regions of the studied area

The analysis of gear shift indicator test results

Analizirani su rezultati dobijeni ispitivanjima prema Pravilniku (EU) 65/2012, koji se odnosi na indikatore promene stepena prenosa, na 59 različitih vozila. Osnovni parametri analize su vrednosti brzine vozila pri kojima indikator preporučuje promenu stepena prenosa i njihova odstupanja od standardnih brzina u kojima se menjaju prenosni odnosi u toku ispitivanja izduvne emisije prema Testu I UNECE pravilnika broj 83, pri čemu je zaključeno da standardne brzine treba revidirati. Analizirane su i relativne uštede goriva za slučajeve promene stepena prenosa prema indikatoru i prema standardnim brzinama (prosečna 5,2%, maksimalna 19,9%). Takođe, pokazano je da sledeći preporuke indikatora, automatski menjači u manuelnom modu pružaju mogućnost veće uštede nego manuelni menjači. Zaključeno je da se statistička analiza o tome u kojoj meri vozači poštuju preporuke indikatora može iskoristiti za unapređenje trenutno važećih ispitivanja samih indikatora, potrošnje goriva i izduvne emisije.The results of tests according to Regulation (EU) No 65/2012 regarding gear shift indicators on 59 different vehicles are analyzed. Primary parameters were the vehicle speeds at which the gear shift is indicated through gear shift indicator (GSI), and based on their deviation from standard gear shift points defined for type I emission tests in UNECE Regulation No 83, it is concluded that standard gear shift points need to be revised. Relative fuel savings when shifting according to GSI instructions compared to standard gear shift points were analyzed (average 5.2%, maximum 19.9%). It is also shown that automaatic transmission gave bigger fuel saving when manual mode is used according to GSI, compared to manual transmission, also used with GSI. It is concluded that statistical analysis on how drivers follow GSI instructions may be used to improve current test procedures for GSI efficiency, fuel consumption measurement and emission tests

The analysis of gear shift indicator test results

Analizirani su rezultati dobijeni ispitivanjima prema Pravilniku (EU) 65/2012, koji se odnosi na indikatore promene stepena prenosa, na 59 različitih vozila. Osnovni parametri analize su vrednosti brzine vozila pri kojima indikator preporučuje promenu stepena prenosa i njihova odstupanja od standardnih brzina u kojima se menjaju prenosni odnosi u toku ispitivanja izduvne emisije prema Testu I UNECE pravilnika broj 83, pri čemu je zaključeno da standardne brzine treba revidirati. Analizirane su i relativne uštede goriva za slučajeve promene stepena prenosa prema indikatoru i prema standardnim brzinama (prosečna 5,2%, maksimalna 19,9%). Takođe, pokazano je da sledeći preporuke indikatora, automatski menjači u manuelnom modu pružaju mogućnost veće uštede nego manuelni menjači. Zaključeno je da se statistička analiza o tome u kojoj meri vozači poštuju preporuke indikatora može iskoristiti za unapređenje trenutno važećih ispitivanja samih indikatora, potrošnje goriva i izduvne emisije.The results of tests according to Regulation (EU) No 65/2012 regarding gear shift indicators on 59 different vehicles are analyzed. Primary parameters were the vehicle speeds at which the gear shift is indicated through gear shift indicator (GSI), and based on their deviation from standard gear shift points defined for type I emission tests in UNECE Regulation No 83, it is concluded that standard gear shift points need to be revised. Relative fuel savings when shifting according to GSI instructions compared to standard gear shift points were analyzed (average 5.2%, maximum 19.9%). It is also shown that automaatic transmission gave bigger fuel saving when manual mode is used according to GSI, compared to manual transmission, also used with GSI. It is concluded that statistical analysis on how drivers follow GSI instructions may be used to improve current test procedures for GSI efficiency, fuel consumption measurement and emission tests

Assessment of Reference Frame Stability trough offset detection in GPS coordinate time series

Сажетак: Предмет овог рада је истраживање доприноса временских серија GPS координата развоју Међународног Терестричког Референтног Фрејма ITRF. Анализа GPS сетова података би требало да детектује не само могуће трендове већ би такође требало да открије офсете или дисконтинуитете узроковане природним процесима као што су изненадна крустална померања или земљотреси као и оних померања која су нису узрокована природним догађајима, односно људском делатношћу. Abstract. The subject of this paper is to investigate the contribution of GPS coordinate time series to the development of the International Terrestrial Reference Frame (ITRF). The analysis of the GPS data sets should not only detect possible trends but should also discover offsets or discontinuities caused by natural processes like sudden crustal movements and earthquakes, as well as those caused by artificial events and man-made activities. This kind of analysis is important because it contributes to the understanding of Reference Frame stability and enables deeper insight into local, regional, and global geodynamical processes. The paper describes the strategy and some results obtained by the analysis of data from Reference GNSS stations located in the Republic of Serbia

Assessment of Reference Frame Stability trough offset detection in GPS coordinate time series

Сажетак: Предмет овог рада је истраживање доприноса временских серија GPS координата развоју Међународног Терестричког Референтног Фрејма ITRF. Анализа GPS сетова података би требало да детектује не само могуће трендове већ би такође требало да открије офсете или дисконтинуитете узроковане природним процесима као што су изненадна крустална померања или земљотреси као и оних померања која су нису узрокована природним догађајима, односно људском делатношћу. Abstract. The subject of this paper is to investigate the contribution of GPS coordinate time series to the development of the International Terrestrial Reference Frame (ITRF). The analysis of the GPS data sets should not only detect possible trends but should also discover offsets or discontinuities caused by natural processes like sudden crustal movements and earthquakes, as well as those caused by artificial events and man-made activities. This kind of analysis is important because it contributes to the understanding of Reference Frame stability and enables deeper insight into local, regional, and global geodynamical processes. The paper describes the strategy and some results obtained by the analysis of data from Reference GNSS stations located in the Republic of Serbia

Water Supply System Performance Improvement in the Town of Pirot Using Water Balance IWA Methodology and Numerical Simulations

The methods for performance measuring and benchmarking proposed by IWA Water Loss Task Force has been adopted worldwide during the last two decades. This methodology and active water loss management is still poorly applied in Serbian water supply systems. This research presents application of hydraulic modelling to estimate water supply network performance in the town of Pirot in Eastern Serbia and evaluate potential effects of active leakage management for water saving using IWA best practice. In the hydraulic model, diurnal demand multipliers for total and registered consumption and leakage exponent are calibrated for the extended period simulation. Calibrated model is then used for hydraulic analysis to estimate system water loss reduction, improvement of the technical performance indicator values and financial savings for the system subdivided in seven pressure management zones. The system pressure control with ten pressure reduction valves was simulated, for two different scenarios: a) using pressure reducing valves with fixed outlet pressure and b) with pressure sustaining valves to maintain the minimum pressure in the zone reference node. Both the resulting water balance and system technical performance indicators are significantly improved in both simulated pressure management scenarios

Application of vehicle's can based network in transmission service load data acquisition

The implementation of various electronic subsystems in passenger cars and different kinds of on-road and off-road vehicles is constantly expanding. Accordingly the new vehicles, instead of being mechanical systems, become advanced mechatronic systems whose development and testing call for a new approach. Possibility of using data available on vehicles network seems to be extremely powerful tool on it. The paper deals with a new approach for service load data measurement and acquisition as a helpful tool in development and testing of vehicles. Based on complexity of the system and different communication protocols on the vehicles' networks it was found as extremely practical solution to make approach which will be based on standards which are widely accepted by the industry. The new approach is based on hardware and software platform oriented to the main vehicle controllers with the task to acquire data which exist on the network and which are relevant to the transmission service load. The said hardware as well as software utilities have to enable computer based monitoring of the vehicle systems behaviour and in that way to be the tool for new vehicles development. The new system was tested in real service. It was found that the system can enable significantly less time of vehicle instrumentation before testing and accurate data acquisition

Application of vehicle's can based network in transmission service load data acquisition

The implementation of various electronic subsystems in passenger cars and different kinds of on-road and off-road vehicles is constantly expanding. Accordingly the new vehicles, instead of being mechanical systems, become advanced mechatronic systems whose development and testing call for a new approach. Possibility of using data available on vehicles network seems to be extremely powerful tool on it. The paper deals with a new approach for service load data measurement and acquisition as a helpful tool in development and testing of vehicles. Based on complexity of the system and different communication protocols on the vehicles' networks it was found as extremely practical solution to make approach which will be based on standards which are widely accepted by the industry. The new approach is based on hardware and software platform oriented to the main vehicle controllers with the task to acquire data which exist on the network and which are relevant to the transmission service load. The said hardware as well as software utilities have to enable computer based monitoring of the vehicle systems behaviour and in that way to be the tool for new vehicles development. The new system was tested in real service. It was found that the system can enable significantly less time of vehicle instrumentation before testing and accurate data acquisition

The future (and the present) of motor vehicle propulsion systems

Limited reserves of oil and the increasing environmental effect of its usage as a motor fuel represent global issue related to the constantly increasing number of motor vehicles. Therefore, the reduction of the fossil fuel consumed and the emission produced in internal combustion engines is the primary goal of the development of motor vehicle propulsion systems. In that sense, the present and the future of motor vehicles relies on hybrid drive systems, electric drive systems and drive systems which use hydrogen as a fuel (either by its combustion or by production of electric energy with the help of fuel cells). In this paper, the authors have presented the aforementioned motor vehicle propulsion systems by explaining their function and design, their basic elements and their functions. Authors have also analysed advantages and disadvantages of the mentioned propulsion systems in comparison to conventional internal combustion engine based systems, both technically and environmentally speaking, but also in relation to available infrastructure and energy resources

Impact of the damper characteristics on the behavior of suspension system and the whole vehicle

Damper asymmetry is a phenomenon for which there is no confirmed explanation in the literature, although it is present in almost all variants of telescopic dampers. This paper analyzes the influence of various characteristics of dampers, both symmetrical and asymmetrical, on the behavior of the suspension system and the whole vehicle. Different tests have been carried out, and they simulate the different types of vehicle movement that are present in exploitation. The simulation was performed in CarSim 8 software package for the vehicle with chosen characteristics. Appropriate conclusions were drawn on the basis of the conducted research, i.e. the differences in the behavior of the suspension system and the vehicle depending on the selected characteristics of the damper are shown