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Probabilistic evaluation of the resistance to low-cycle deformation and failure of the critical components in the equipment used in the energy, engineering, metallurgy, chemical, shipbuilding, and other industries is of primary importance with the view towards their secure operation, in particular, given the high level of cyclic loading acting on the equipment during its operation. Until recently, systematic probabilistic evaluation has been generally applied to the results of statistical and fatigue investigations. Very few investigations applying this approach to the low-cycle domain. The present study aims to substantiate the use of probabilistic calculation in the low-cycle domain by systematic probabilistic evaluation of the diagrams of cyclic elastoplastic deformation and durability of the materials representing the major types of cyclic properties (hardening, softening, stabilization) and investigation of the correlation relationships between mechanical properties and cyclic deformation and failure parameters. The experimental methodology that includes the calculated design of the probabilistic fatigue curves is also developed and the curves are compared to the results of the experiment. Probabilistic values of mechanical characteristics were determined and calculated low-cycle fatigue curves corresponding to different failure probabilities, to assess them from the probabilistic perspective. A comparison of low-cycle fatigue curves has shown that the durability curves generated for some materials using analytical expressions are not accurate. According to the analysis of the relative values of experimental probabilities of low-cycle fatigue curves, the use of analytical expressions to build the curves can lead to a significant error. The results obtained allow for the revision of the load bearing capacity and life of the structural elements subjected to cyclic elastoplastic loading in view of the potential scattering of mechanical properties and resistance parameters to low-cycle deformation and failure. In addition, the results enable determination of the scatter tolerances, depending on the criticality of the part or structure. [ABSTRACT FROM AUTHOR]

Abstract: By the method of data collation, research into changes in life histories (ignition delay plus time of combustion) of the compounded fuel droplets (diesel fuel–biodiesel fuel (RME)–bioethanol), as well as diesel engine D-144 brake specific fuel consumption rates was performed and obtained results being compared to diesel fuel by an analogous manner. An optimum composition of the multi-component blend B30+7.5E demonstrating specific fuel consumption rates and droplet combustion characteristics very similar to diesel fuel was derived. In comparison to B30, a newly derived combustible blend demonstrated fairly improved emissions of exhaust gases. For low load mode: smoke opacity (−10%), NO X (−2%), CO (−20%), and HC (−12.5%). For average load mode: smoke opacity (−10%), NO X (−2%), CO (−22%), and HC (−14.5%). For high load mode: smoke opacity (−18%), NO X (−2%), CO (−22%), and HC (−18%). [Copyright &y& Elsevier]

Abstract: District heating sector is one of the most important sectors of Lithuanian energy industry. Consequently, low-cost bioenergy sources could play an important role in developing biofuels based on the so-called second-generation feedstock and decentralized energy supply for remote rural areas with low heat demand density. The present amount of biomass straw is already considerable in Lithuania but the potential is even much higher. It is assumed that the share of firewood in the balance of RES will decrease significantly – from 86.7% in 2009 to 55% in 2020 and future decisions on the acceptability of new substitutes must be found. The most important factors that could hasten the diffusion of straw combustion technologies for heat-only boilers (HOBs) in order to contribute to a local fuel and low-emission energy infrastructure are political issues, reduction in existing technical thresholds, market and economic conditions, international cooperation activity, and broad experience through wood residue combustion. The collected data indicated that under conditions in Lithuania, biomass straw combustion is prospective mainly to be used for heat production in small and medium scale units of 0.6–5.0MWth capacity as well as in large scale installations where multi-biomass strategies are foreseen. [Copyright &y& Elsevier]