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[en] According to the data of the Estonian Statistics Department the consumption of fuels in Estonia over the period of January-June 1993 was a follows: coal 77,053 t, oil shale 7,981,840 t, fuel peat 127,376 t, peat briquette 42,041 t, firewood 154,511 solid metres, wood chip 55,648 solid metres. The consumption of fuel peat (chiefly for producing briquette) was more considerable in the town of Kohtla-Jaerve and in the districts of Paernu and Tartu where Estonia's major peat-briquette plants are located. The share of peat in the other industries has been less significant. (author)
[en] This study investigates the dynamics of traffic containing human-driven vehicles along with a fraction of self-organized artificial intelligence (AI) autonomous vehicles (AVs) on multilane freeways. We propose guidelines for the development of AI agents, such that a small fraction of AVs forms local constellations that significantly accelerate the entire traffic flow while reducing fuel consumption and increasing safety. Specifically, we report a 40% enhancement in traffic flow efficiency and up to a 28% reduction in fuel consumption even when only 5% of vehicles are autonomous. This scenario does not require changes to current infrastructure or communication between vehicles; it only requires proper regulations. The results indicate that more efficient, safer, faster, and greener traffic flow can be realized in the near future. (paper)
[en] After decades of limited situational awareness for aircraft flying in the mid-North Atlantic, full satellite coverage will soon be available. This opens up the possibility of altering flight routes to exploit the wind field fully. By considering flights between New York and London, from 1 December, 2019 to 29 February, 2020, it is shown how changes to current practice could significantly reduce fuel use and, hence, greenhouse gas emissions. When airspeed and altitude are constant, the fuel flow rate per unit time is constant and the route with the minimum journey time uses the least fuel. Optimal control theory is used to find these minimum time routes through wind fields from a global atmospheric re-analysis dataset. The total fuel burn and, hence, the emissions (including CO2) are proportional to the ‘air distance’ (the product of airspeed and flight time). Minimum-time routes are compared with the actual routes flown through the wind fields. Results show that current flight tracks have air distances that are typically several hundred kilometres longer than the fuel-optimised routes. Potential air distance savings range from 0.7% to 7.8% when flying west and from 0.7% to 16.4% when flying east, depending on airspeed and which of the current daily tracks is used. Thus, substantial reductions in fuel consumption are possible in the short term. This is in contrast to the incremental improvements in fuel-efficiency through technological advances, which are high cost, high risk and take many years to implement. (paper)
[en] Past investigations have shown that the current type-approval test cycles are not representative for real-world vehicle usage. Consequently, the emissions and fuel consumption of the vehicles are underestimated. Therefore, a new cycle is being developed in the UNECE framework (World-harmonised Light-duty Test Procedure, WLTP), aiming at a more dynamic and worldwide harmonised test cycle. To provide recommendations for the new cycle, we have analysed the noxious emission results of a test programme of seven vehicles on the test cycles NEDC (New European Driving Cycle) and CADC (Common Artemis Driving Cycles). This paper presents the results of that analysis to show the zones of the cycle that are causing the highest emissions, using two different approaches. Both approaches show that the zones with the highest emissions of modern vehicles differ from vehicle to vehicle. Consequently, a representative test cycle has to contain as many combinations of vehicle speed and acceleration that occur in real-world traffic as possible to prevent that a vehicle does not perform well for certain combinations because they are not included in the test cycle. Furthermore, the paper demonstrates that it is important to include a cold start to ensure rapid warm up of the catalysts. - Highlights: ► Vehicle emissions on the NEDC and CADC type-approval cycles are analysed. ► The zones within the cycles that produce the highest emissions are investigated. ► It is shown that these zones can differ significantly from one vehicle to another. ► The WLTP cycle should contain as many of the real-world driving zones as possible.
[en] Currently, automotive bodies are constructed usually using a single material, e.g. steel or aluminum. Compared to single-material automotive bodies, multi-material automotive bodies allow optimal material selection in each structural component for higher product performance and lower cost. This paper presents novel material performance indices and procedures developed to guide systematic material selection for multi-material automotive bodies. These new indices enable to characterize the crashworthiness performance of complex-shaped thin-walled beams in multi-material automotive bodies according to material types. This paper also illustrates the application of these performance indices and procedures by designing a lightweight multi-material automotive body. These procedures will help to design a lightweight and affordable body favored by the automotive industry, thus to reduce fuel consumption and greenhouse gas emissions.
[en] This paper estimates the demand for gasoline in Kuwait for the period 1970-89 using a cointegration and error correction model (ECM). It is found that gasoline demand is inelastic with respect to price in the short and long run, and while it is elastic in the long run, gasoline demand is inelastic with respect to income in the short run. This suggests that gasoline demand response to income changes is higher in the long run than in the short run. Furthermore, gasoline consumption adjusts towards its long-run level with about 52% of the adjustment occurring in the first year. (author)
[en] In this paper, hydrogen is considered as a renewable and sustainable solution for minimizing the fossil fuel based-global irreversibility coefficient of global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions such as global waste exergy factor, global irreversibility coefficient and hydrogen based-global exergetic indicator. In order to investigate the role of hydrogen use at minimizing the fossil fuel based global irreversibility, the actual fossil fuel consumption data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases, the fossil fuel based-global irreversibility coefficient will decrease. (author)
[en] Current US policies have failed to significantly reduce the country's enormous gasoline consumption. A new multipronged approach comprising a gasoline tax, attribute based CAFE standards, and other supplementary initiatives such as alternative fuels and public transit is required. In combination, these policies can achieve a far greater reduction in gasoline consumption than any one could alone. Only through such a broad range of policies can serious headway be made to reduce the current overdependence. (Author)
[en] The conference paper deals with new frontiers and barricades in the global economic development and their influence on fuel consumption and energy source development. Topics discussed are incremental energy supply - new frontiers, world car population - new frontiers, OPEC crude production capacity vs call on OPEC, incremental world oil demand by region 1992-2000, oil resource cost curve, progress in seismic 1983-1991, Troll picture, cost reduction in renewables, sustained growth scenario, nuclear electricity capacity - France, OECD road transport fuels - barricades, and energy taxation. 18 figs
[en] In this article, a survey is given of Byelorussian peat reserves and peat industry. Problems related to peat scientific research, new peat technologies and products of Byelorussia are dealt with, while those of peat chemical industry are considered more thoroughly. (author)