A set of introgression lines from S. peruvianum PI 126944 into the genetic background of cultivated tomato (S. lycopersicum) is being developed. Several generations were derived from three interspecific hybrids previously obtained. A lot of crosses and embryo rescue were required to obtain until the third backcross, due to the high incompatibility existing between tomato and PI 126944. Crosses between F1 plants allowed the obtaining of a pseudo-F2 generation. The same procedure was followed until pseudo-F6 generation. Additional crosses between plants of different generations were made in order to increase progeny. Among a total number of 263 molecular markers tested, 105 resulted polymorphic between tomato and PI 126944. This set of polymorphic markers consisted in 90 Simple Sequence Repeats and 15 Cleaved Amplified Polymorphic Sequences. Generations available were genotyped with these markers, observing a progressive reduction in the S. peruvianum genome in the most advanced. A reduction of incompatibility was achieved as a consequence of the S. peruvianum genome reduction. In addition, S. peruvianum genome was almost completely represented considering the different plants of the most advanced generations, so the set of ILs will be basically developed from them. Tomato yellow leaf curl virus (TYLCV) and Tomato spotted wilt virus (TSWV) resistance was evaluated in some generations, having been successfully introgressed and expressed into tomato background.
The lack of lateral resistance in a curved railway track can produce misalignment problems due to the centrifugal forces when the trains pass through. Moreover, most of the times continuous welded rails (CWR) are used in nowadays railway tracks, which can induce the track buckling as a result of thermal loads caused by high temperature gradients. A new sleeper has been designed to provide higher lateral resistance of the track. A finite element model has been developed to analyze the lateral movements of an actual curved track subjected to lateral resistance problems. Then, variations on the finite element model have been made to study the response of the track when different sleepers are used. Thus, the performance of the different sleepers in the modeled track has been analyzed, resulting that the inclusion of the new sleeper in the track can improve the lateral resistance between 39 and 55 % with respect to a track with conventional sleepers made of wood or concrete.
In recent years, there has been a significant increase in the development of the railway system. Despite the huge benefits of railways, one of the main drawbacks of this mode of transport is vibrations caused by vehicles in service, especially in the case of trams circulating in urban areas. Moreover, this undesirable phenomenon may be exacerbated by the presence of irregularities in the rail-wheel contact. Thus, an analytical model able to reproduce the vibrational behavior of a real stretch of tram track was implemented. Besides, a simulation of different types of corrugation was carried out by calculating in an auxiliary model the dynamic overloads generated by corrugation. These dynamic overloads fed the main model to obtain the vibrations generated and then transmitted to the track.
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