Cognitive evolution of transport spatiality

This study aims to provide an overview of the cognitive evolution of transport related to spatial theorems. The study recalls the various economic theories and criticizes them. It also reviews their methodology and their transport connection, with spatial focus. It can be stated that in the last two hundred years, spatiality appeared in transport related economics modelling, meanwhile sustainability or environmental protection are not in the scope of such models yet. Therefore, new area is to emerge, in which sustainability will be in focus

Analysis of Customer Service Quality Models and for their Approbation Opportunities in Aviation

The article examines tools, which may be used to assess service quality in aviation and to analyze service quality models. Many experts analyzing customer service state that a good customer service is one of the most important reasons for customer satisfaction and loyalty. This is particularly important in aviation customer service, because aviation services are subject to higher requirements due to the specifics of the service. In pursuit of the top-level customer service, refining customer needs and expectations becomes very important, because knowing customer expectations allows purposefully focusing the customer service process based on them and achieving high customer satisfaction. Also, the nature of customer service in aviation is different; here staff must be trained with more scrutiny and examples of specific situations.In order to investigate the quality of customer service, conducting a theoretical analysis of customer needs or service criteria alone is not sufficient. Customer service quality is perceived differently due to a variety of factors, thus service quality models are used to find out customer expectations or to identify service gaps, also helping to conduct analyses and to improve processes. The analysis of customer service models revealed that they have not been adapted for aviation due to the following: their focus on a single service factor, the lack of relationship between components, neglected role of employees in customer service, and the like

Research into the quality of fuels and their biocomponents

The article provides a closer look into the quality properties of fuels, analyses the merits and demerits of using biocomponents in petrol and diesel and overviews the ways of improving the quality of fuels. Work carried out by the authors covers the determination of the basic quality properties (density, kinematic viscosity and flash point) of petrol, diesel, methanol, ethanol, buthanol as well as rape methyl and rape ethyl esters. The paper investigates how these qualities influence the operational performance of the engine and puts forward the age‐dependence analysis of diesel quality properties. First published online: 27 Oct 201

The Analysis of Vibration Signals of Critical Points of the Bus Body Frame

In this paper, authors have investigated wave distribution caused by the mechanical structure of a passenger bus body frame and its parameters based on the theory of covariance functions. Authors have measured the intensity of vibrations at fixed points. Time scale analyses were conducted based on data arrays (matrixes). The estimates of covariance functions clearly showed that changes in the state of the bus mechanical structure invariably impact changes of the intensity of vibration signals at the relevant points. In the analysis, software Matlab 7 was applied

Research of Parameters of a Compression Ignition Engine Using Various Fuel Mixtures of Hydrotreated Vegetable Oil (HVO) and Fatty Acid Esters (FAE)

The present study is aimed at studying the energy and environmental performance at various engine loads (BMEP) with identical start of injection (SOI) for all fuel types. The combustion parameters for the fuel mixtures were analyzed using the AVL BOOST software (BURN subroutine). Five different blends were tested, consisting completely of renewable raw materials based on hydrotreated vegetable oil (HVO) and fatty acid methyl ester (FE100), and the properties of diesel fuel (D) were compared with respect to these blends. The mixtures were mixed in the following proportions: FE25 (FE25HVO75), FE50 (FE50HVO50), FE75 (FE75HVO25). In this study, diesel exhaust was found to produce higher NOx values compared to FE blends, with HVO being the lowest. Hydrocarbon and smoke emissions were also significantly lower for blends than for diesel. Possible explanations are the physical properties and fatty acid composition of fuel mixtures, affecting injection and further combustion. The results showed that blends containing more unsaturated fatty acids release more nitrogen oxides, thus having a lower thermal efficiency compared to HVO. No essential differences in CO emissions between D and HVO were observed. An increase in this indicator was observed at low loads for mixtures with ester. CO2 was reduced in emissions for HVO compared to the aforementioned blends and diesel. The results of the combustion analysis show that with a high content of unsaturated fatty acids, mixtures have a longer combustion time than diesel fuel.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

The Assessment of Importance of the Factors that Predetermine the Quality of a Service of Transportation by Road Vehicles

AbstractStriving for satisfaction of the needs of clients is the principal task in any sector of economy, including transportation by road vehicles. In course of the grow of the demand for transportation services, the number of enterprises offering the transportation services grows increasingly in national and international markets of European states. To survive in the competition struggle upon the high level of supply of such services in the international market, Lithuanian carriers should ensure their competitive advantage over carriers from other countries. The purpose of the paper is to analyze what criteria of the quality of a transportation service predetermine a competitiveness of such services and what factors mostly impact the key service quality criteria. The object of the research includes the factors that may affect the criteria of the quality of a transportation service

Analysis of the influence of fatigue on passenger transport drivers’ performance capacity

The article deals with the influence of professional drivers’ fatigue on the occurrence of traffic events. The study of various scientific works on the causes of traffic events related to human psychophysiological qualities has revealed that all of these works highlight the complex work process of a driver as an operator of a certain mechanism. It is governed by the regulatory documents reviewed in this article. Driver's fatigue is a quite frequent accident-causing human factor. Building upon the results of the study on human idiosyncrasies, the authors suggest a methodology for professional selection of drivers. This methodology is based on practical data, i.e. on a comprehensive analysis of performance peculiarities of professional drivers employed at Joint-Stock Company ‘Vilnius Public Transport’ (in Lithuanian – UAB ‘Vilniaus viešasis transportas’). Application of the suggested methodology enables to reduce the number of road accidents caused by city passenger transport drivers by up to 40÷50%. The article proposes a methodology for compilation of professional selection criteria for passenger transport drivers, also applicable to drivers working in other transportation areas, as well as to employees of field investigation services and other persons who constantly face nervous and emotional stress and experience a lack of information and time

Efficient hydrotreated vegetable oil combustion under partially premixed conditions with heavy exhaust gas recirculation

This study performed a detailed analysis of combustion and emission characteristics of a single-cylinder compression ignition engine fuelled with diesel, hydrogenated vegetable oil (HVO) and their blend (50/50). Taking advantage of the high reactivity of HVO, the aim was to investigate how changes in fuel injection and exhaust gas recirculation (EGR) strategies can achieve partially premixed combustion with superior efficiency and ultra-low engine-out emissions. Without EGR, and with a multi-pulse injection strategy optimized for diesel, combustion timings were the same for all three investigated fuels. HVO exhibited higher tolerance to EGR in terms of combustion retarding, so it was possible to use high recirculation rates. This reduced nitrogen oxides, while maintaining high indicated efficiency. The pilot injection control allowed further extending the EGR dilution limit without incurring trade-offs with combustion efficiency and related carbon monoxide and unburned hydrocarbon emissions. Additionally, heavy EGR conditions supported reduction of soot for all three tested fuels. However, the best trade-off between soot and other emission compounds was observed for HVO. HVO also resulted in the lowest emissions of aldehydes and aromatics. In conclusion, on the given engine platform at a steady-state, mid-load operating point, HVO allowed for 43% indicated thermal efficiency with engine-out nitrogen oxides and carbon monoxide emissions near to Euro VI limits. This efficiency level was 1.5 percentage points above that for the optimized diesel operation.fi=vertaisarvioitu|en=peerReviewed

Comparative investigations into energetic and ecological parameters of camelina-based biofuel used in the 1Z diesel engine

The paper presents the findings of comparative investigations into the operation of Audi 80 1.9l 4 cylinder diesel engine, TDI, type 1Z, 66 kW powered by new FAME (fatty acid methyl esters) mixtures of spring (SCME) and winter (WCME) camelina-based biofuel and mineral diesel. The article assesses the principles of operating electronic control over the diesel engine (ECS) and exhaust gas recirculation (EGR) and looks at a positive impact of the system on energetic (be, ηe) and ecological (CH, NOx, CO2, SM) parameters. The ECS of the average and maximal power of the engine improve in-cylinder air injection that has an impact on an increase in ηe by approximately 30% and reduces the emission of the harmful components from incomplete combustion. It is accepted that in case diesel fuel is replaced by FAME biofuels (RME – rapeseed methyl ester; SCME – spring camelina methyl ester; WCME – winter camelina methyl ester), ECS control parameters shall not be retrofitted or additionally optimized. The properties of camelina-based biofuel mixtures B30 (SCME) and B30 (WCME) and diesel fuel are similar to the properties of the standard mixtures of RME biofuel B30 (RME). If compared to diesel fuel, the use of camelina-based biofuel mixtures B30 (SCME) and B30 (WCME) enables lower emissions of harmful components from exhaust gases, which makes approximately 15% of CH and 20÷25% of SM

Betterment of ecological parameters of a diesel engine using Brown‘s gas

Hydrogen could become an important element, allowing us to accumulate and transfer energy in a clean way. Hydrogen can be used in cars as a fuel additive which increases the combustion efficiency of the fuel-air mixture. A small amount of hydrogen gas could also be produced in a car by decomposing water by means of electrolysis, using for this purpose the energy produced by the car's electric power generator. The hydrogen and oxygen (HHO) mixture obtained, which is also known as Brown's gaseous mixture, is supplied to the engine's intake manifold. Tests have been performed with 1.6 TD (SB) diesel engine. The automobile was tested on a chassis dynamometer running at a different speed. The engine was tested using fuel-air combustion mixture and fuel-air-HHO gas combustion mixture without additional adjustment of the fuel supply system. The test results have revealed that additional injection of HHO gas into combustion mixture resulted in up increase of fuel consumption, but the CO, the HC, the PM amount has decreased insignificantly. At few engine loads the amount of NOx decreased, however increasing the engine load resulted in a gradual increase. Having analysed test results we came to a conclusion that additional supply of HHO gas into combustion mixture resulted in improvement of the combustion quality of fuel-air mixture and ecological performance of the engine. This is especially relevant for the automobiles which are not equipped with a supplementary exhaust gas toxicity decreasing system. First published online: 11 Oct 201