11 research outputs found

    ALTERNATIVE OPTIONS FOR GAMES AND ENTERTAINMENT FOR CHILDREN OVER 12 YEARS OLD

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    Teenagers are not welcome in playgrounds - parents recognize them as a risk to younger children and the city government - to the facilities, but what teenagers suffer from is a place where they can gather and do something together. If the municipality provides decent open spaces for teenagers to know as themselves and a place to socialize without public pressure, then they will be able to channel their energy in a constructive way and the public opinion of teenagers will improve

    CONVERSION OF VACANT INDUSTRIAL LAND INTO YOUTH PLAY AREAS

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    In the limited volume of the article, we will only consider activities that can gain added value when implemented in a post-industrial environment, not activities for teenagers in general. Attention has been paid to activities that can benefit from elements specific to the specific environment - building stock, materials, etc. The article examines the potential of these areas to create plots that better suit teenagers and the possibilities for adhoc transformations in play spaces that better meet the complex needs of teenagers for outdoor activities

    System for studying the parameters of gas solenoid valves

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    The aim of the present work is to construct a test stand for determining the characteristics of different fourth generation gas injectors working under various conditions as close as possible to the actual operating ones. For this purpose, the standard fourth generation gas system and liquefied petroleum gas (LPG) as a working fluid were used for the stand. A system has been developed to maintain the gas leakage pressure equal in value to the pressure in the intake manifold of a Spark Ignition (SI) engine. Used LPG is compressed and liquefied for reuse. Additionally, safety measures are taken. The stand provides the right conditions for determining the influence of the nozzle diameter, the length of the connecting pipe between the injector and the intake manifold, the differential pressure upstream and downstream of the injector and other factors that affect these characteristics, which may be different when installing LPG system to an internal combustion engine

    Comparative life cycle impact assessment of a battery electric and a conventional powertrains for a passenger transport ferryboat : A case study of the entire integrated system for vessel propulsion

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    This master thesis represents a life cycle impact assessment of a state of the art electrically driven power train. It is expected to be installed in a diesel engine passenger ferry boat, currently transporting passengers in downtown Stockholm archipelago. The assessment has a comparative character in between the currently operating and the new power train in order to differentiate and recognize which of the two propulsion options is the environmentally preferable choice. The scope of the study is directed towards the thorough examination of both power trains so that it can represent most closely the two specific technological cases. Studied and assessed were the three main life cycle phases of each power train – raw materials acquisition and manufacturing, use phase and end of life phase. The fundament of the study involved creating environmental models for each and every component of the drive trains, the propulsion fuel and energy used, and the services related to waste treatment in the last phase of their functional life. The environmental models were later used to build live cycle inventories that served to derive the respectful impact from the item analyzed. The data used to model the battery electric power train was provided directly from the manufacturer, where the end of life procedures carried out were assumed where possible. The main battery pack for the electric power train was not modeled in terms of  end of life procedures due to insufficiency of information. Almost no generic information was available to model the diesel engine and it was calculated by creating auxiliary simplified cad models. The rest of the data required to achieve an environmental inventory regarding the power train was available from a subcontractor. Both studied options were modeled with allocation approach that includes the avoided production of materials at the waste treatment stage where there was sufficient information to do that. There was none to model the main battery packs avoided production which is a major component of the battery electric system. To model the use phase of the diesel engine power train, research data regarding combustion emissions and waterborne emissions was utilized. A number of electricity mix models were applied to create a sensitivity analysis of the operation phase of the battery electric power train. Chosen for baseline scenarios simulating the use phases of both power trains are use of Nordel market electricity mix and the combustion of low sulfur diesel with five volumetric percent rape methyl ester additive. For the purposes of the assessment eighteen midpoint impact indicators were used to cover the areas of global warming potential, human health and quality of eco systems. The results from the study show that the estimated impact from both power trains is small enough to have almost no influence on the results from the two baseline scenarios. Based on this it was concluded that for future research of similar cases either generic information can be used or a cut-off can be applied. After the assessment, more environmentally favorable was estimated the diesel engine power train because of the large burdens from the battery manufacturing in the battery electric option. Further assessment determined that the diesel engine power train again is less environmentally intensive than the battery electric with the main battery burdens excluded. In the overall life cycle impact assessment both power train showed different results in the different impact categories, which could not place a definitive propulsion option of choice. The conclusions from the analysis are that the diesel engine power train causes higher impact in the categories related to global warming, fossil depletion and in most ecosystems quality indicators. The battery electric version in its base line scenario, on the other hand, expresses higher impact in categories related to human health and in the remaining eco system quality midpoint-scores

    Energy flow analysis based on a simulated drive of a hybrid locomotive powered by fuel cells

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    Implementation of hybrid drives in rail vehicles is a solution aimed at limiting the negative environmental impact of transport. The use of fuel cell systems is a contemporary trend in the development of locomotives. The paper presents an energy flow analysis in a hybrid locomotive powered using fuel cells. The parallel hybrid drive system consisted of fuel cells, batteries and an electric motor. The simulations and analyzes were performed with the use of AVL Cruise M software. A simulated route, with a length of approximately 300 km, was used as basis for the analysis, taking into account a typical speed profile of a locomotive in passenger traffic. The energy flow and consumption values were estimated, and mean hydrogen consumption values were determined

    Optimization of biogas composition in experimental studies

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    The article is focused on the potential and application of biogas, as an alternative fuel from Renewable Energy Sources, for use mainly in gas-generator stations. Biogas fuel is basically a mixture of methane and carbon dioxide. Its composition depends on the type of raw material used for its production. Methane concentration in biogas is between 50÷80%. To be possible engine to work with maximum efficiency with different biogas fuels, it is necessary to modify specific adjustment parameters depending on the concentration of methane in the mixture. This requires the creation of a biogas simulation system for different concentrations of the main components. The aim is to investigate and determine the optimum and permissible biofuel blend concentrations and their impact on engine performance and fuel consumption. Biogas can be used as a fuel to produce electricity, heat or steam or as fuel for internal combustion engine, and its use will help to reduce harmful emissions into the atmosphere

    Fuel with a higher content of bio components in greenhouse effect aspects

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    Transport is an energy-intensive sector of the economy and it is important where energy comes from and how it is used - now and in the future. The presented research results seem to encourage further work, despite the fact that the work had the character of basic research. The results were achieved in idealized conditions by the fact that the internal combustion engine was tested in static conditions on the test bench and the fuels contained components with strictly defined parameters. These conditions are different from everyday life. However, the obtained results seem to be valuable as they lead to conclusions regarding biofuels, and these conclusions are not directly formulated and published in the literature on the subject. The general conclusion from the research carried out is that the introduction of the so-called biofuels can contribute not to the reduction of CO2 emissions, but to its faster balancing in the environment. This balancing can be achieved but at the cost of increased fuel consumption. This increase in fuel consumption would probably not occur if the "bio" components in the fuel were synthetic hydrocarbons obtained from biomass. However, proving it requires wider studies, including LCA. Data for this LCA, especially about a fuel consumption, may be coming from long term operation of vehicles

    Fuel with a higher content of bio components in greenhouse effect aspects

    No full text
    Transport is an energy-intensive sector of the economy and it is important where energy comes from and how it is used - now and in the future. The presented research results seem to encourage further work, despite the fact that the work had the character of basic research. The results were achieved in idealized conditions by the fact that the internal combustion engine was tested in static conditions on the test bench and the fuels contained components with strictly defined parameters. These conditions are different from everyday life. However, the obtained results seem to be valuable as they lead to conclusions regarding biofuels, and these conclusions are not directly formulated and published in the literature on the subject. The general conclusion from the research carried out is that the introduction of the so-called biofuels can contribute not to the reduction of CO2 emissions, but to its faster balancing in the environment. This balancing can be achieved but at the cost of increased fuel consumption. This increase in fuel consumption would probably not occur if the "bio" components in the fuel were synthetic hydrocarbons obtained from biomass. However, proving it requires wider studies, including LCA. Data for this LCA, especially about a fuel consumption, may be coming from long term operation of vehicles

    The vehicle driver safety prediction system

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    The article presents analysis of road crash accidents. It presents the evolution of safety systems, starting from a description of the curently used vehicle-based systems, with particular emphasis on the prediction of the driver falling asleep. The article also proposes a proprietary system of sleep prediction based on the face detection of drivers. The detection of facial landmarks is presented as a two-step process: an algorithm finds faces in general, and then needs to localize key facial structures within the face region of interest. The article presents the operation of the algorithm to detect driver falling asleep; method of detection and analysis

    Improving In-Context Few-Shot Learning via Self-Supervised Training

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    Self-supervised pretraining has made few-shot learning possible for many NLP tasks. But the pretraining objectives are not typically adapted specifically for in-context few-shot learning. In this paper, we propose to use self-supervision in an intermediate training stage between pretraining and downstream few-shot usage with the goal to teach the model to perform in-context few shot learning. We propose and evaluate four self-supervised objectives on two benchmarks. We find that the intermediate self-supervision stage produces models that outperform strong baselines. Ablation study shows that several factors affect the downstream performance, such as the amount of training data and the diversity of the self-supervised objectives. Human-annotated cross-task supervision and self-supervision are complementary. Qualitative analysis suggests that the self-supervised-trained models are better at following task requirements.Comment: NAACL 202
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