Railway operations, time-tabling and control

This paper concentrates on organising, planning and managing the train movement in a network. The three classic management levels for rail planning, i.e., strategic, tactical and operational, are introduced followed by decision support systems for rail traffic control. In addition, included in this paper are discussions on train operating forms, railway traffic control and train dispatching problems, rail yard technical schemes and performance of terminals, as well as timetable design. A description of analytical methods, simulation techniques and specific computer packages for analysing and evaluating the behaviour of rail systems and networks is also provided

Optimal Policies Search for Sensor Management

International audienceThis paper introduces a new approach to solve sensor management problems. Classically sensor management problems can be well formalized as Partially-Observed Markov Decision Processes (POMPD). The original approach developped here consists in deriving the optimal parameterized policy based on a stochastic gradient estimation. We assume in this work that it is possible to learn the optimal policy off-line (in simulation ) using models of the environement and of the sensor(s). The learned policy can then be used to manage the sensor(s). In order to approximate the gradient in a stochastic context, we introduce a new method to approximate the gradient, based on Infinitesimal Perturbation Approximation (IPA). The effectiveness of this general framework is illustrated by the managing of an Electronically Scanned Array Radar. First simulations results are finally proposed

Modelling of wear and crack initiation in rails / Gordana .

PhD ThesisThe ‘Dynarat’ computer simulation of ratcheting wear and failure of rail steel has been developed at Newcastle University over the past decade based on laboratory tests and analysis of British normal grade (R220) rail steel. The aim of this thesis is to develop material models for Dynarat that can be used to predict wear and rail life for R260 rail steel, which is used widely in Europe and increasingly in Britain, and also for newer premium grade pearlitic rail steels. Laboratory twin-disc testing and metallurgical material analysis were used to obtain data for characterising and modelling material response to repeated loading. The relationship between material hardness and plastic shear strain is central to the material model used in the Dynarat simulation, and is determined for the materials tested here by studying the measured hardness and plastic strain. Additional calibration of the wear rate was achieved by performing Dynarat simulations that closely matched the laboratory tests. In addition to the material model development, the contact stress model used by Dynarat for modelling wheel-rail contact is improved. Previously the driving stress for plastic strain accumulation was the orthogonal shear stress in the plane of the simulation. In the new model, plastic strain accumulation is now made directional, with components in the x and y directions. Partial slip is now implemented in the 3D simulation, to approximate the real wheel-rail contact, with both contact region and adhesive zone modelled as ellipses. Two types of high-speed train at two curves on the UK’s East Coast Main Line have been simulated with the new computer model to study the effects of traffic mixtures. Wear rates and time until crack initiation are obtained. The new model provides a tool to help rail/wheel manufacturers to choose the best steel, and for maintenance personnel to predict rail wear and cracks, and thus to help plan grinding schedules in order to optimise rail life and safety

Laboratory simulation of low-adhesion leaf film on rail steel

Low-adhesion (i.e., low-friction) problems continue to plague the modern railway, particularly in autumn when leaves on the line and damp conditions combine to form a low-adhesion contaminant film on the railhead. Sudden drops in adhesion can cause havoc with timetables, and can lead to accidents, electrical insulation by contaminants can cause problems with track circuitry. Using laboratory twin-disk testing, a number of techniques for reproducing the leaf-film have been tried, and the adhesion behaviour of the resultant contaminant films is investigated. Misty conditions are found to be the best for producing low-adhesion leaf films

A Deficiência de vitamina d está associada com níveis aumentados de il-17 e tnfα em pacientes com insuficiência cardíaca crônica

FUNDAMENTO: Estudos recentes revelaram uma forte associação entre o estado de vitamina D (VD) e a insuficiência cardíaca crônica (ICC). Hoje, é normalmente aceito que a resposta imune pró-inflamatória é subjacente ao desenvolvimento de ICC. OBJETIVO: Uma vez que a VD possui propriedades anti-inflamatórias, pesquisamos o seu impacto sobre as citocinas envolvidas na ICC, como TNFα e IL-17, em pacientes portadores de ICC. MÉTODOS: Foi extraído sangue de quarenta pacientes com ICC secundária à hipertensão arterial e/ou doença coronariana. Os níveis de VD status, IL-17 e TNFαforam avaliados através de 25-hidroxi VD3 EIA e ELISA de citocinas. Também foram realizadas avaliação clínica e ecocardiograma. RESULTADOS: Pacientes idosos com ICC em Nis (Sudeste da Europa, latitude 43ºN) apresentaram níveis de 25-hidroxi VD3 abaixo do normal. Nossos dados demonstraram que pacientes com ICC secundária à hipertensão arterial têm níveis significativamente menores de 25-hidroxi VD3, e maiores de TNFαe IL-17A, se comparados com os níveis de pacientes com ICC secundária à doença coronariana. CONCLUSÃO: É demonstrado aqui que, mesmo em regiões com muitos dias ensolarados a deficiência de VD é motivo de preocupação. Os dados sugerem que o déficit de VD contribui para os elevados níveis de IL-17 e TNFα e, assim, contribuir ao desenvolvimento de ICC

Stereospecific ligands and their complexes. IV: Synthesis, characterization and cytotoxicity of novel platinum(IV) complexes with ethylenediamine-N,N '-di-S,S-2-propanoate and halogenido ligands: Crystal structure of s-cis-[Pt(S,S-eddp)Cl-2]center dot 4H(

The syntheses of two novel platinum(IV) complexes of formula [PtX2(S,S-eddp)center dot nH(2)O (S,S-eddp = ethylenediamine-N,N'-di-S,S-2-propanoate ion, X = chlorido (1) or bromido (2), n = 4, 0) are reported. The complexes have been obtained by direct reaction of corresponding potassium hexahalogenidoplatinate(IV) with neutralized ethylenediamine-N,N'-di-S,S-2-propanoic acid (H-2-S,S-eddp). The complexes were characterized by elemental analysis, infrared, H-1 and C-13 NMR spectroscopy. The spectroscopically predicted geometrical configurations of the obtained complexes were confirmed by X-ray analyses of the crystal structures of the s-cis-[Pt(S,S-eddp)Cl-2]center dot 4H(2)O and uns-cis-[Pt(S,S-eddp)Br-2]. These complexes displayed significantly lower in vitro cytotoxicity in comparison to cisplatin. (c) 2010 Elsevier Ltd. All rights reserved

COVID-19 testing and vaccine willingness: Cross-sectional survey in a culturally diverse community in Sydney, Australia

The current study examined patterns in COVID-19 testing and vaccination intentions across multiple language groups in Greater Western Sydney, Australia. Participants completed a cross-sectional survey available from March 21 to July 9, 2021 in Sydney, Australia. Surveys were available in English or translated (11 languages). Participants could complete surveys independently or with support from bilingual staff. Logistic regression models using post-stratification weighted frequencies identified factors associated with testing and vaccination intentions. Most of the 708 participants (88%, n=622) were not born in Australia; 31% reported that they did not speak English well or at all (n=220); 70% had no tertiary qualifications (n=497); and 41% had inadequate health literacy (n=290). Most participants reported high testing intention (77.2%, n=546), with differences observed across language groups (p<0.001). The most frequently reported barrier to testing was concerns about infection at the clinic (26.1%). Half (53.0%) reported willingness to get a COVID-19 vaccine if recommended to them (n=375); 18% were unwilling (n=127), and the remainder unsure (29%, n=205). These proportions varied significantly by language group (p<0.001). Participants were more likely to be unwilling/hesitant if they were female (p=0.02) or did not use Australian commercial information sources (p=0.01). Concerns about side effects (30.4%, n=102) and safety (23.9%, n=80), were key reported barriers to vaccination. Different language groups have unique and specific needs to support uptake of COVID-19 testing and vaccination. Health services must work collaboratively with culturally and linguistically diverse communities to provide tailored support to encourage COVID-19 testing and vaccination. 708 adults living in Sydney, Australia, who did not speak English as their main language at home took part in a survey about COVID-19 vaccination and testing. Participants could complete the survey online (English/translated) or with support from bilingual staff. The survey was available in 11 languages. Three quarters of participants (77%) reported they would get tested for COVID-19 if they had symptoms ‘no matter what.’ The most common barrier was concern about getting infected at the testing clinic. 53% of participants reported that they would get a COVID-19 vaccine if it was recommended to them. 18% reported that they wouldn’t get the vaccine, and 29% were unsure. The main barriers were concerns about vaccine side effects and safety. Intentions to get tested for COVID-19 or to get vaccinated varied significantly across language groups. Participants who were female, or who did not use Australian commercial information sources were more likely to be unwilling or unsure about getting a COVID-19 vaccine. Different language groups have unique and specific needs to support uptake of COVID-19 testing and vaccination. Health services must work collaboratively with culturally and linguistically diverse communities to provide tailored support to encourage COVID-19 testing and vaccination

Psychological, social and financial impacts of COVID-19 on culturally and linguistically diverse communities in Sydney, Australia

OBJECTIVE: To explore the psychological, social and financial outcomes of COVID-19-and the sociodemographic predictors of those outcomes-among culturally and linguistically diverse communities in Sydney, Australia. DESIGN: Cross-sectional survey informed by the Framework for Culturally Competent Health Research conducted between March and July 2021. SETTING: Participants who primarily speak a language other than English at home were recruited from Greater Western Sydney, New South Wales. PARTICIPANTS: 708 community members (mean age: 45.4 years (range 18-91)). 88% (n=622) were born outside of Australia, 31% (n=220) did not speak English well or at all, and 41% (n=290) had inadequate health literacy. OUTCOME MEASURES: Thirteen items regarding COVID-19-related psychological, social and financial outcomes were adapted from validated scales, previous surveys or co-designed in partnership with Multicultural Health and interpreter service staff. Logistic regression models (using poststratification weighted frequencies) were used to identify sociodemographic predictors of outcomes. Surveys were available in English or translated (11 languages). RESULTS: In this analysis, conducted prior to the 2021 COVID-19 outbreak in Sydney, 25% of the sample reported feeling nervous or stressed most/all of the time and 22% felt lonely or alone most/all of the time. A quarter of participants reported negative impacts on their spousal relationships as a result of COVID-19 and most parents reported that their children were less active (64%), had more screen time (63%) and were finding school harder (45%). Mean financial burden was 2.9/5 (95% CI 2.8 to 2.9). Regression analyses consistently showed more negative outcomes for those with comorbidities and differences across language groups. CONCLUSION: Culturally and linguistically diverse communities experience significant psychological, social and financial impacts of COVID-19. A whole-of-government approach is needed to support rapid co-design of culturally safe support packages in response to COVID-19 and other national health emergencies, tailored appropriately to specific language groups and accounting for pre-existing health disparities