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1.
Influence of biodiesel on injection, fuel spray, and engine characteristics
Breda Kegl, Stanislav Pehan, 2008, original scientific article

Abstract: This paper discusses the influence of biodiesel on the injection, spray, and engine characteristics with the aim to reduce harmful emissions. The considered engine is a bus diesel engine with injection M system. The injection, fuel spray, and engine characteristics, obtained with biodiesel, are compared to those obtained with mineral diesel under peak torque and ratedconditions. The considered fuel is neat biodiesel from rapeseed oil. Its density, viscosity, surface tension, and sound velocity are determined experimentally and compared to those of mineral diesel. The experimentally obtained results are used to analyze the most important injection, fuel spray, and engine characteristics. Furthermore, the influence of biodiesel usage on lubrication is presented briefly. The results indicate that, by using biodiesel, harmful emissions (NOx, CO, HC, smoke, and PM) can be reduced to some extent by adjusting the injection pump timing properly while keeping other engine characteristics within acceptable limits. Furthermore, the results indicate better lubrication conditions when biodiesel is used.
Keywords: biodiesel, diesel engine, injection characteristics, fuel spray, emission, lubrication
Published: 31.05.2012; Views: 1051; Downloads: 190
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2.
Numerical analysis of injection characteristics using biodiesel fuel
Breda Kegl, 2006, original scientific article

Abstract: This paper deals with numerical analysis of injection process using biodieselžmineral diesel fuel blends with the aim to search for the potentialsto reduce engine harmful emissions. The considered fuels are neat biodiesel from rapeseed oil and its blends with mineral diesel D2. For the numerical analysis a one-dimensional mathematical model is employed. In order to model accurately the investigated fuels, the employed empirical expressionsfor their properties are determined by experiments. To verify the mathematical model and the empirical expressions, experiments and numerical simulation are run on a mechanical control diesel fuel injection M system at several operating regimes. Injection process at many different operating regimes and using several fuel blends are then investigated numerically. Attention is focused on the injection characteristics, especially on fuelling,fuelling at some stage of injection, mean injection rate, mean injection pressure, injection delay and injection timing, which influence the most important engine characteristics. The analysis of the obtained results reveals that, while keeping engine performance within acceptable limits, harmful emissions can be reduced by adjusting appropriately pump injection timing in dependence on the biodiesel content. This prediction is also confirmed experimentally.
Keywords: internal combustion engines, Diesel engines, fuel injection, biodiesel fuel, numerical simulation, emission reduction
Published: 31.05.2012; Views: 1209; Downloads: 64
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Solar energised transport solution and customer preferences and opinions about alternative fuel vehicles
Matjaž Knez, Marjan Sternad, 2015, original scientific article

Abstract: Authorities in Slovenia and other EU member states are confronted with problems of city transportation. Fossil-fuel based transport poses two chief problems - local and global pollution, and dwindling supplies and ever increasing costs. An elegant solution is to gradually replace the present automobile fleet with low emission vehicles. This article first explores the economics and practical viability of the provision of solar electricity for the charging of electric vehicles by installation of economical available PV modules and secondly the customer preferences and opinions about alternative low emission vehicles. Present estimates indicate that for the prevailing solar climate of Celje - a medium-sized Slovenian town - the cost would be only 2.11 EUR cents/kWh of generated solar electricity. Other results have also revealed that the most relevant factor for purchasing low emission vehicle is total vehicle price.
Keywords: solar photovoltaic, low emission vehicles, electric vehicles, sustainable transport, logistics
Published: 17.07.2017; Views: 387; Downloads: 48
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5.
Acoustic emission detection of macro-cracks on engraving tool steel inserts during the injection molding cycle using PZT sensors
Rajko Svečko, Dragan Kusić, Tomaž Kek, Andrej Sarjaš, Aleš Hančič, Janez Grum, 2013, original scientific article

Abstract: This paper presents an improved monitoring system for the failure detection ofen graving tool steel inserts during the injection molding cycle. This system uses acoustic emission PZT sensors mounted through acoustic waveguides on the engraving insert. We were thus able to clearly distinguish the defect through measured AE signals. Two engraving tool steel inserts were tested during the production of standard test specimens, each under the same processing conditions. By closely comparing the captured AE signals on both engraving inserts during the filling and packing stages, we were able to detect the presence of macro-cracks on one engraving insert. Gabor wavelet analysis was used for closer examination of the captured AE signalsć peak amplitudes during the filling and packing stages. The obtained results revealed that such a system could be used successfully as an improved tool for monitoring the integrity of an injection molding process.
Keywords: injection molding, process monitoring, acoustic emission, PZT sensors, piezoelectric effect
Published: 22.06.2017; Views: 535; Downloads: 224
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6.
Experimental investigation review of biodiesel usage in bus diesel engine
Breda Kegl, Marko Kegl, 2017, original scientific article

Abstract: This paper assembles and analyses extensive experimental research work conducted for several years in relation to biodiesel usage in a MAN bus Diesel engine with M injection system. At first the most important properties of the actually used neat rapeseed biodiesel fuel and its blends with mineral diesel are discussed and compared to that of mineral diesel. Then the injection, fuel spray, and engine characteristics for various considered fuel blends are compared at various ambient conditions, with special emphasis on the influence of low temperature on fueling. Furthermore, for each tested fuel the optimal injection pump timing is determined. The obtained optimal injection pump timings for individual fuels are then used to determine and discuss the most important injection and combustion characteristics, engine performance, as well as the emission, economy, and tribology characteristics of the engine at all modes of emission test cycles test. The results show that for each tested fuel it is possible to find the optimized injection pump timing, which enables acceptable engine characteristics at all modes of the emission test cycles test.
Keywords: bus diesel engine, fuel injection, fuel spray, combustion, emission, engine performance, tribology characteristics, optimized injection pump timing
Published: 07.07.2017; Views: 417; Downloads: 224
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7.
Policies for promotion of electric vehicles and factors influencing consumers' purchasing decisions of low emission vehicles
Matjaž Knez, Matevž Obrecht, 2017, original scientific article

Abstract: Recently different studies of green transport have become interesting for policy makers, car manufacturers, customers and energy suppliers. Many stakeholders from the public and private sectors are investing a lot of effort to identify consumer behaviour for future improvements in development of green products and effective strategies, which could accelerate the transition to sustainable future. This paper presents the effects of electric vehicle promotional policies and customer preferences about alternative fuel vehicles. This study has shown that the electric vehicle promotional policies adopted in Slovenia have been unsuccessful, as the share of first-time registered electric vehicles in 2013 was below 1%. For different segments of people whose opinions about low emission vehicles differ, different measures must be adopted. When designing promotional policies focus must be on the most relevant factors such as the total vehicle price and fuel economy.
Keywords: policies, low emission vehicles, electric vehicles, purchasing, consumers, green logistics, green transport, Slovenia
Published: 04.08.2017; Views: 367; Downloads: 250
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8.
Technological systems (TS) waste minimization, waste-free and environmentally friendly production
Manuela Ingaldi, Dorota Klimecka-Tatar, 2016, independent scientific component part or a chapter in a monograph

Keywords: technological systems, waste management, emission, pollution, companies
Published: 11.05.2018; Views: 571; Downloads: 45
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