Railway track degradation modelling using dynamic multi-regression to predict failure patterns

Railway tracks degrade and may eventually break down due to several operational and environmental impacts that affect the rails’ reliability. The most common type of railhead defect is called the rail squat, which cost Network Rail an estimate of approximately 3.9 million pounds annually. Squat defects are minor subsurface laminations that run diagonally down the running surface and spread laterally and longitudinally over and along the rail tracks (Li, Zili et al., 2008a; Li, Zili et al., 2008b; Li, Z., 2009). The occurrence of squat defects has a significant impact on the track performance, leading to speed restrictions, delays, and cancellation of in-service train operations and hence penalties for infrastructure owners. To ensure the performance and efficiency of service operations and more reliable railway infrastructure, the UK is investing in railway modernization projects to meet this demand (Rail director April 2023, 2023; MyBib Contributors, 2019).This study uses a Dynamic Multiple linear regression to model the relationship between squat defects and influential parameters such as track length, maximum permissible speed, maximum axle load, estimated million gross tonnage, tamping frequency, rail grinding frequency, and corrugation frequency detection. A hazard model is proposed and used to predict transition probabilities between defect and failure. This research evaluated six years of data acquired from network rail on squats defects, grinding maintenance, and corrugation faults across the UK railway network. The dynamic Markov model is used within the scope of the hazard model to determine the transition probabilities of squat defects propagation. A complete squat data analysis is performed by comparing the efficiency of the rail gridding maintenance regime to the cumulative squat defect frequency against the number of repair operations. An example simulation is shown to anticipate the time to breakdown of railway track systems

The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals

Implementation of image matching correlation of symmetrized dot pattern of vibration signals in fault diagnosis cold test method for diesel engines

TSTM is an annual publication edited and printed by the Editorial Office of the Department of Academic Research from the Engineering Faculty - University of Bacau. It contains the most recent theoretical and experimental studies concerning the topical and perspective problems in the conception and manufacturing fields of the technological plants and equipments. The work is edited under the aegis of the Bacau University and Romanian Academy of Technical Sciences, the Committee of Scientific reviewers and coordinating editors including an impressive teaching staff from the departments of specialty from Foreign and Romanian Universities

EFFECT OF LAG ON THE SYMMETRIZED DOT PATTERN (SDP) DISPLAYS OF THE VIBRATION SIGNAL OF DIESEL ENGINES

TSTM is an annual publication edited and printed by the Editorial Office of the Department of Academic Research from the Engineering Faculty - University of Bacau. It contains the most recent theoretical and experimental studies concerning the topical and perspective problems in the conception and manufacturing fields of the technological plants and equipments. The work is edited under the aegis of the Bacau University and Romanian Academy of Technical Sciences, the Committee of Scientific reviewers and coordinating editors including an impressive teaching staff from the departments of specialty from Foreign and Romanian Universities

Condition Monitoring in Diesel Engines for Cold Test Applications. Part I: Vibration Analysis for Pass/Fail Decision

none4In this paper the characteristics of the cold test technology will be described and a monitoring method for quality tests of diesel engines at the end of assembly line will be considered. A variety of different techniques for processing vibration signals has been proposed by many researchers but only a few applications in cold test monitoring exist. The determination of reliable threshold values for pass/fail decision through the calculation of global parameters which describe the PDF (Probability Density Function) of the vibration signal in the time domain is the goal of this work. Experiments on normal and faulty engines were carried out in order to develop this approach. In particular, eight different faults were artificially introduced and the influence of the operational speed during tests is investigated. Furthermore, a comparison between measurements concerning vibrations, pressure and torque is shown and discussed.noneS. Delvecchio; G. Dalpiaz; O. Niculita; A. RivolaS. Delvecchio; G. Dalpiaz; O. Niculita; A. Rivol