The article discusses the research on CO 2 emissions at the stage of electric engine vehicle operation. The operation stage includes, among others use of the vehicle as well as maintenance and charging for the vehicle's propulsion. The origin of the electricity consumed during charging has an impact on the vehicle's emissions balance. The scope of considerations concerns coal as the main energy carrier in Poland. The obtained results can be a benchmark for comparing other primary energy sources used for electricity production. Based on the collected technical data of electric cars, the values of CO 2 emission factors from electricity production in thermal power plants and data on the state and structure of electricity production in Poland, an analysis of CO 2 emissions from electric vehicles in the operational stage was performed. The vehicle's electricity consumption of 0.14-0.16 kWh/ km is accompanied by CO 2 emissions of 100.94-115.36 g/km. The calculated CO 2 exceeds the EU limit value from 01/01/2020 (95 g/km) for average CO 2 emissions from new passenger vehicles. The main message of the work is the statement that increasing the efficiency of the electricity generation process in commercial thermal power plants in Poland will translate into a reduction in the emission of electric cars consuming this energy for propulsion. The research shows that the change in the efficiency of energy transformations in a thermal power plant from 38% to 46% leads to a reduction in the emission of an electric vehicle by over 17%. The emission of CO 2 from a passenger car with a compression-ignition engine is discussed. The considerations include the stage of the use of the vehicle and the stage of production of diesel oil, which is consumed during the use of the vehicle.
The concern of this article is the analysis of the impact of increased volume (dilation) and decreased strength of the rock material in the plastic zone on the displacement field in the vicinity of the roadway. Elastic-plastic model of the behaviour of the rock material and the strength criterion of Coulomb-Mohr were assumed. The volume change of the rock material is controlled by the angle of dilation ψ, which determines dilation parameter β that is taken into account in the analysis. The influence of parameter β and the strength of the rock material, after crossing the border state of stress, in the field of displacements in the vicinity of the excavation and rock pressure on the elastic support of the excavation was proved. The relationships determining displacement fields in the plastic zone which were obtained with consideration to in this zone of both the elastic and plastic displacement, as well as the relationships which were obtained without elastic deformations was discussed. The exact form of the equation for the displacement field in the plastic zone depends on how the elastic deformation in the plastic zone is defined. There are three ways of describing these deformations. In the first method it is assumed that in plastic deformation area the elastic deformation constants are equal to the deformation constants at the plastic and elastic border. The second method of description is based on the assumption that the plastic zone is a thick-walled ring whose edges: internal and external have been appropriately debited. In the third method, elastic deformations in the plastic zone were made dependent on the state of stress in the zone. The results are illustrated in a form of response curves of the rock mass.Keywords: state of displacement, roadway, elastic-plastic model, response curve of the rock mass, dilatation, decreased strength of rock material, reducing the strength of the rock material, Coulomb-Mohr criterion.
The use of modern vehicles may contribute to limiting the adverse impact of urban transport on the environment. Evaluation of the options for choosing new means of transport in terms of economic and ecological benefits allows for the identification of the most advantageous variants. The solution is to consider replacing a bus compliant with a Euro III norm (base variant) with a one compliant with Euro VI (option 1) or with an electric counterpart (option 2). The evaluation of the solutions was based on the calculated parameters: a monetary value reflecting the energy cost of the analyzed buses and the ecological effect of the reduced emissions from the Euro VI bus or the electric bus compared with the Euro III vehicle. The ecological effect resulting from the use of the electric bus was determined taking into account the emissions from fossil fuels (coal, natural gas) and biomass. The method of cost analysis was used to evaluate the solution of replacing older buses with new ones (with different types of propulsion). It is based on calculating the unit cost of achieving the ecological effect of the solution.
The waste management system in health care is a tool that allows to conduct reasonable steps to reduce their amount, collection, storage and transport, and provide a high level of utilization or disposal. Logistics solutions in waste management are intended to make full use of the infrastructure and technical resources, optimize costs, ensure the safety and health at work and meet legal requirements. The article discusses the elements of the logistics system of waste management in hospital, necessary to ensure the smooth flow of waste from its origin to landfilling. The following criteria were characterized: technical and technological, ecological and economic that can be used in the analysis and evaluation of solutions in waste management in the hospital. Finally, solutions to improve waste management system in the hospital on the example of the real object have been presented.
The paper considers plastic products in terms of energy consumption at two stages of their life cycle, i.e. at the stage of production of virgin polymers and at the stage of processing polymers into a finished product. Energy intake places were indicated and energy needs related to the production of polymer products were assessed. This allowed to indicate which polymer production and processing processes into finished products are particularly energy-intensive. The research shows that the greater the amount of energy accumulated in the plastic during its production, the greater the importance of this plastic in the post-consumer phase as a recyclable material. Recycling of waste plastics allows the use of this energy and reduces the consumption of virgin raw materials. Primary polymers were compared in terms of the energy efficiency index of their production process. This indicator is the quotient of the calorific value of the polymer and the energy consumption in its production. It shows how much of the energy input during the production of primary plastic can be recovered from the thermal processing of the waste plastic. The highest indicator value was obtained for polyethylene and polypropylene. It was found shown that the total energy consumption (converted to primary energy) of the PET virgin polymer production process and its processing into packaging reaches the value of 109.2-115.2 MJ/kg. This is almost five times the calorific value of this polymer.
The study aimed to determine the mass concentration of PM10 in the air in urban area. The specific objective of the research was to analyze and assess the impact of transport road emissions on the level of concentration of particulate matter in the atmosphere in the Lublin agglomeration. The measuring points were located in places at different distances from the communications emission sources and, at the same time, possibly varying degrees of air pollution dust. Measuring the concentration of dust at the measuring points was performed using an indirect method using a laser photometer. In the research point which was not under direct influence of a heavy traffic road dust levels lower by 10.5% to 65.4% than in the vicinity of the transport route were reported. Small particle air pollution at all the points covered by the study increased significantly during the heating season. Based on the comparison of the obtained values of PM10 concentrations with legal standards, it was found that the air pollution exceeded the limits in all measurement points only during a series of measurements in the months of November-December. The recorded increase in air pollution during the heating season should be associated with an increased dust emissions in this period from the "low" emitters -local house boilers and detached houses.
Determination of the global uniaxial compressive strength of rock mass on the basis of the Hoek-Brown failure criterion requires knowledge of the strength parameters: cohesion and the angle of internal friction. In the conventional method for the determination of these parameters given by Balmer, they are expressed by the minimum principal stress. Thus, this method does not allow for the assessment of an impact of hydrostatic pressure and stress path on the value of cohesion, friction angle and global uniaxial compression of rock mass. This problem can be eliminated by using the Hoek-Brown criterion expressed by the invariants of the stress state. The influence of hydrostatic pressure and the Lode angle on the strength parameters of the rock mass was analysed.
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