Analysis and prediction of tram track degradation

Transportation is the means to carry people and goods from one place to another, and has been very important in each stage of human civilization. Therefore, engineers have developed the transportation network day-by-day, aiming to provide for people’s comfort, needs and safety in the most sustainable way possible. In the past, transport organisations generally concentrated on the construction and expansion of transport networks, but they have gradually moved from a focus on expansion to intelligently maintaining the existing assets in recent years. For this reason, degradation models have been developed in many transport management systems, with the aim of assisting track maintenance planning and reducing the costs of asset management. Melbourne has the largest operating tram network in the world with 250 kilometers of double track (Yarra Trams, 2017a). Melbourne’s tram network is operated by the Yarra Trams organisation under franchise from the government of Victoria, Australia (Yarra Trams, 2017a). Yarra Trams organises the news, maps, timetables, service changes, real-time tram arrival information, and the construction and maintenance of the tram infrastructure. Many variables are involved in ensuring that Melbourne tram system operates to safe and best practice standards. One of the main elements influencing the tram system is the track infrastructure. The condition of the track infrastructure affects network operations either directly or indirectly. In order to keep the track infrastructure in its best condition over the longest possible time period, a maintenance plan is required. This plan is essential for such a large network as it can help in recovering the serviceability of tram tracks from faults and damage and prevent further wear of the tracks. Currently, manual inspections are still used to identify track maintenance activities across the network. These inspections identify the status of the tram tracks, whether the tracks need maintenance, the required level of maintenance and the time period needed to maintain the damaged tracks. Since the inspections are done by a number of maintenance teams, human errors are likely to occur. In addition, inaccurate prediction of the maintenance time frame and mistakes in the inspection and detection of track defects may occur. Therefore, prioritisation of the maintenance activities is a substantial challenge. High maintenance and operational costs may be the result of poorly planned maintenance schedules. In other words, very early or late maintenance of the tram tracks are very costly, as are unnecessary maintenance or replacement of tracks. In order to solve this problem, this research investigates degradation models for tram tracks in Melbourne. The models are rigorously reviewed in order to determine the most appropriate model in terms of sustainability, safety, accuracy and long-term behaviour. A time-series stochastic model is developed using MATLAB software to predict the degradation of tram tracks. A regression model is also developed using SPSS software for comparison with the time-series model. The models are developed for straight and curves sections of the tram network. The models were developed after analysing tram track variables over a period of time to find the relationship between the variables and track degradation. The variables include asset data variables (such as construction material, track surface, rail profile) and operational variables (such as annual rail usage, number of trips, route location). In this research, the annual rail usage (in million gross tons (MGTs)) is found to be the main variable affecting rail degradation using the gauge parameter of rails for curves and straight sections of the tram network. Based on the developed prediction models, the maintenance activities of degraded rail tracks are identified within a specified time period. This will help to reduce the maintenance costs, save time and prevent occasional unnecessary maintenance activities. In addition, it will reduce interruptions to traffic and delays experienced by passengers

Credit Rating Agency Announcements and the Eurozone Sovereign Debt Crisis

This paper studies the impact of credit rating agency (CRA) announcements on the value of the Euro and the yields of French, Italian, German and Spanish long-term sovereign bonds during the culmination of the Eurozone debt crisis in 2011-2012. The employed GARCH models show that CRA downgrade announcements negatively affected the value of the Euro currency and also increased its volatility. Downgrading increased the yields of French, Italian and Spanish bonds but lowered the German bond's yields, although Germany's rating status was never touched by CRA. There is no evidence for Granger causality from bond yields to rating announcements. We infer from these findings that CRA announcements significantly influenced crisis-time capital allocation in the Eurozone. Their downgradings caused investors to rebalance their portfolios across member countries, out of ailing states' debt into more stable borrowers' securities

Early Clinical Manifestations Associated with Death from Visceral Leishmaniasis

The visceral leishmaniasis (VL) is a disease potentially fatal if not diagnosed and treated opportunely. This article presents the results of the study on the manifestations identified at the time of the clinical suspicion of the VL cases. This study was conducted in Belo Horizonte, the capital of the State of Minas Gerais, located in southeastern Brazil. This study is both timely and substantive because the Belo Horizonte is an area of transmission of VL, with one of the highest VL-death proportions of Brazil. The patients with higher risk of death had at least one of the following characteristics: ≥60 years, weakness, HIV co-infection, bleeding, jaundice and other associated infections. During the period 2002–2009, 8% to 22% of the patients with VL progressed to death in Belo Horizonte, whilst the proportion in the country was much lower and varied between 5% and 9%. This study has identified vulnerable patients who are at higher risk of death from VL and who would benefit from early predictive evaluation of the prognostic. Hence, the knowledge regarding the factors associated with death may contribute for clinical management and for reduction of deaths from VL

Precise measurement of 2 νββ decay of 100 Mo with the CUPID-Mo detection technology

We report the measurement of the two-neutrino double-beta (2 νββ) decay of 100Mo to the ground state of 100Ru using lithium molybdate (Li2100MoO4) scintillating bolometers. The detectors were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory (France). From a total exposure of 42.235 kg× day, the half-life of 100Mo is determined to be T1/22ν=[7.12-0.14+0.18(stat.)±0.10(syst.)]×1018 years. This is the most accurate determination of the 2 νββ half-life of 100Mo to date

The Genetic Structure of Leishmania infantum Populations in Brazil and Its Possible Association with the Transmission Cycle of Visceral Leishmaniasis

Leishmania infantum is the etiologic agent of visceral leishmaniasis (VL) in the Americas, Mediterranean basin and West and Central Asia. Although the geographic structure of L. infantum populations from the Old World have been described, few studies have addressed the population structure of this parasite in the Neotropical region. We employed 14 microsatellites to analyze the population structure of the L. infantum strains isolated from humans and dogs from most of the Brazilian states endemic for VL and from Paraguay. The results indicate a low genetic diversity, high inbreeding estimates and a depletion of heterozygotes, which together indicate a predominantly clonal breeding system, but signs of sexual events are also present. Three populations were identified from the clustering analysis, and they were well supported by F statistics inferences and partially corroborated by distance-based. POP1 (111 strains) was observed in all but one endemic area. POP2 (31 strains) is also well-dispersed, but it was the predominant population in Mato Grosso (MT). POP3 (31 strains) was less dispersed, and it was observed primarily in Mato Grosso do Sul (MS). Strains originated from an outbreak of canine VL in Southern Brazil were grouped in POP1 with those from Paraguay, which corroborates the hypothesis of dispersal from Northeastern Argentina and Paraguay. The distribution of VL in MS seems to follow the west-east construction of the Bolivia-Brazil pipeline from Corumbá municipality. This may have resulted in a strong association of POP3 and Lutzomyia cruzi, which is the main VL vector in Corumbá, and a dispersion of this population in this region that was shaped by human interference. This vector also occurs in MT and may influence the structure of POP2. This paper presents significant advances in the understanding of the population structure of L. infantum in Brazil and its association with eco-epidemiological aspects of VL