Benchmarking of premium rail material wear

Railway steel that offers a greater quality and extended life is described by the industry as premium rail. It is mainly used on areas of rail networks where accelerated wear, rolling contact fatigue or other rail related damage phenomena prevail. However, little performance data exists for these materials and where it does it is limited to a narrow set of contact conditions. The aim of this work was therefore to map premium rail performance across a range of Tγ contact conditions to benchmark against standard grade R260 rail. Laboratory tests using a twin disc machine were performed to determine the wear performance of four premium rail grades against R8 wheel material, at various slip conditions of 1–20%. Comparison with Martensitic Stainless Steel (MSS) laser clad material was made as a further benchmark. The results are shown in terms of Tγ and wear rate for both the rail and wheel discs. Material hardness maps were obtained of the full rail and the laboratory small scale specimen materials in order to correlate hardness with their wear behaviour. The purpose of this work is to understand the likelihood and rate of wear in different wheel/rail contact conditions and to produce enough wear information for the premium rail that could be used in prediction tools for comparison with other materials and contact conditions

Twin disc assessment of wear regime transitions and rolling contact fatigue in R400HT – E8 pairs

Twin disc tests were carried out to evaluate the wear resistance and Rolling Contact Fatigue (RCF) of premium R400HT rail samples in contact with E8 wheel samples. The wear rate and friction coefficient were correlated with the frictional work expended at the contact interface (the Tgamma approach). Accelerated RCF tests were also carried out on the premium R400HT rail and the results were compared to those obtained for standard R260 rail. The wear rates of rail samples were consistently lower than those reported in the literature for other contacting pairs in which the rail material studied is softer than R400HT. Also, the energy needed for the transition from the moderate to severe wear regime significantly increased for the hardened rail. Fatigue cracks were shallower for R400HT when compared with standard rail material. Hardened rails also showed lower mean spacing between fatigue cracks. This new information can be used to improve wear simulations of wheels and rails by using more realistic wear equations

Investigation of the influence of rail hardness on the wear of rail and wheel materials under dry conditions (ICRI wear mapping project)

Some railway managers and practitioners fear that introducing premium rail materials will have a detrimental effect on the wheels of trains that use the line. A review of relevant investigations across all scales in the laboratory, and in the field has been carried out. This showed that, as rail hardness increases, its wear, and overall system wear reduces. Wheel wear does increase with increasing rail hardness, but only for wheels running on rails that are softer than them. Similar trends were observed in all studies, so it seems that the fears were unfounded. While the wear trends appear well characterised some issues have been identified. One relates to the varying work hardening capability of wheel and rail materials. Often only bulk hardness is quoted, but work hardening can increase material surface hardness by up to 2.5 times and make materials that were initially softer, harder than the opposing material. Another related issue is test length. It is essential that enough cycles are applied such that the materials reach steady state wear, i.e., the point at which work hardening has reached its limit. In previous work it is not always clear that steady state wear has been reached. Some gaps have been identified in the current knowledge base, the largest of which is the failure to determine which mechanisms lead to the wear trends seen. Analysis of recent work on different clad layers on rail discs and premium rail materials allowed some of these gaps to be addressed. Results indicated that opposing wheel material hardened to the same level independent of rail hardness. Wheel wear is therefore stress driven under the conditions used, and dictated by the wheel material properties only. At higher slip levels relationships become less clear, but here temperature and therefore hot hardness is most influential and is as yet uncharacterised

SBV Regularity for Genuinely Nonlinear, Strictly Hyperbolic Systems of Conservation Laws in one space dimension

We prove that if $t \mapsto u(t) \in \mathrm {BV}(\R)$ is the entropy solution to a $N \times N$ strictly hyperbolic system of conservation laws with genuinely nonlinear characteristic fields $$u_t + f(u)_x = 0,$$ then up to a countable set of times $\{t_n\}_{n \in \mathbb N}$ the function $u(t)$ is in $\mathrm {SBV}$, i.e. its distributional derivative $u_x$ is a measure with no Cantorian part. The proof is based on the decomposition of $u_x(t)$ into waves belonging to the characteristic families $$u(t) = \sum_{i=1}^N v_i(t) \tilde r_i(t), \quad v_i(t) \in \mathcal M(\R), \ \tilde r_i(t) \in \mathrm R^N,$$ and the balance of the continuous/jump part of the measures $v_i$ in regions bounded by characteristics. To this aim, a new interaction measure \mu_{i,\jump} is introduced, controlling the creation of atoms in the measure $v_i(t)$. The main argument of the proof is that for all $t$ where the Cantorian part of $v_i$ is not 0, either the Glimm functional has a downward jump, or there is a cancellation of waves or the measure $\mu_{i,\mathrm{jump}}$ is positive

Executive function profiles of preschool children with Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder: a systematic review

Background: Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are both associated with differences in Executive Functioning (EF). There is lack of clarity around the specificity or overlap of EF differences in early childhood when both disorders are first emerging. Method: This systematic review aims to delineate preschool EF profiles by examining studies comparing the EF profiles of children with and without ASD or ADHD. Five electronic databases were systematically searched (last search in May 2022) to identify published, quantitative studies of global and specific EF (Inhibition, Shifting, Working Memory, Planning and Attentional Control), comparing children aged 2-6 with a diagnosis of ASD or ADHD to peers without ASD or ADHD. Results: Thirty-one empirical studies (10 ADHD and 21 ASD studies) met criteria for inclusion. EF profiles in preschool ASD were characterised by consistent Shifting, and, in most cases, Inhibition impairments. ADHD studies consistently reported impairments in Inhibition and Planning, and in most cases Working Memory. Findings with regards to sustained Attention and Shifting in ADHD and Working Memory and Planning in ASD were mixed. Conclusions: Overall, current evidence indicates overlap but also some specificity in EF impairments in preschool ASD and ADHD. There were differences in the degree to which individual domains were impaired, with Shifting more consistently impaired in ASD, and Inhibition, Working Memory and Planning in ADHD. Methodological issues and differences in methods of outcome measurement could potentially underlie mixed findings, as informant-based measures revealed more robust EF impairments than laboratory-based tasks

Paternal peripartum depression:emerging issues and questions on prevention, diagnosis and treatment. A consensus report from the cost action Riseup-PPD

Introduction: Paternal peripartum depression (P-PPD) is a serious and understudied public health problem associated with impaired family functioning and child development. The lack of recognition of P-PPD may result in limited access to both information and professional help. Objective: The aim of the study was to review studies on paternal peripartum depression and to identify issues and questions where future research and theory formation are needed. Methods: A literature search for systematic reviews, meta-analyses and primary studies was conducted using PubMed, Web of Science, Embase, Scopus, Medline, PsychInfo and Informit databases. Key results within the retrieved articles were summarised and integrated to address the review objectives. Results: Based on the literature, the knowledge related to prevalence, screening, risk factorsunique to fathers, management strategies and outcomes of P-PPD is lacking. Currently, there is no consensual understanding of the definition of P-PPD and recommendations for dealing with P-PPD. Limited data were available regarding the barriers preventing fathers from accessing support systems. Conclusion: Emerging issues that need to be addressed in future research include: P-PPD definition and pathogenetic pathways; prevention strategies and assessment tools; self-help seeking and engagement with interventions; the cost-effectiveness of P-PPD management; needs of health professionals; effect on child development, and public awareness. Future studies and clinical practice should account the complexities that may arise from the father’s perceptions of health care services. Results from this review highlights the critical issues on how to plan, provide and resource health services, to meet the health needs of fathers.</p

Compassionate faces: Evidence for distinctive facial expressions associated with specific prosocial motivations

Compassion is a complex cognitive, emotional and behavioural process that has important real-world consequences for the self and others. Considering this, it is important to understand how compassion is communicated. The current research investigated the expression and perception of compassion via the face. We generated exemplar images of two compassionate facial expressions induced from two mental imagery tasks with different compassionate motivations (Study 1). Our kind- and empathic compassion faces were perceived differently and the empathic-compassion expression was perceived as best depicting the general definition of compassion (Study 2). Our two composite faces differed in their perceived happiness, kindness, sadness, fear and concern, which speak to their underling motivation and emotional resonance. Finally, both faces were accurately discriminated when presented along a compassion continuum (Study 3). Our results demonstrate two perceptually and functionally distinct facial expressions of compassion, with potentially different consequences for the suffering of others

Rates of depressive and anxiety symptoms in the perinatal period during the COVID-19 pandemic: Comparisons between countries and with pre-pandemic data

Background: The COVID-19 pandemic was a significant threat to perinatal mental health. This study examined differences in clinically significant depression, anxiety, and co-morbid symptoms among pregnant and postpartum women across several countries and compared prevalence of perinatal depression and anxiety before and during the pandemic in each participating country. Methods: Participants were 3326 pregnant and 3939 postpartum women (up to six months postpartum) living in Brazil, Chile, Cyprus, Greece, Israel, Portugal, Spain, Turkey, and the United Kingdom. An online survey was completed between June 7th and October 31st 2020, and included the Edinburgh Postnatal Depression Scale (EPDS) and the Generalized Anxiety Disorder Screener (GAD-7). The pre-pandemic studies were identified through literature review. Results: Prevalence of clinically significant depression (EPDS≥13), anxiety (GAD-7 ≥ 10), and co-morbid (EPDS≥13 and GAD-7 ≥ 10) symptoms was 26.7 %, 20 % and 15.2 %, in pregnant women, and 32.7 %, 26.6 % and 20.3 %, in postpartum women, respectively. Significant between-country differences were found in all mental health indicators in both perinatal periods. Higher levels of symptoms were observed during (versus before) the pandemic, especially among postpartum women. Limitations: Participants were mostly highly educated and cohabiting with a partner. The online nature of the survey may have limited the participation of women from vulnerable socio-economically backgrounds. Conclusions: Our findings expand previous literature on the negative impact of the COVID-19 pandemic on perinatal mental health, by highlighting that this may be influenced by country of residence. Mental health care policies and interventions should consider the unique needs of perinatal women in different parts of the world. © 2022Funding text 1: Sara Cruz acknowledges the Centro de Investigação em Psicologia para o Desenvolvimento (CIPD) [The Psychology for Positive Development Research Center] ( UID/PSI/04375 ), Lusíada University North, Porto, supported by national funds through the Portuguese Foundation for Science and Technology , I.P., and the Portuguese Ministry of Science, Technology and Higher Education ( UID/PSI/04375/2019 ).; Funding text 2: This paper is part of the COST Action Riseup-PPD CA18138 and was supported by COST under COST Action Riseup-PPD CA18138 . ; Funding text 3: Vera Mateus received financial support from CAPES /PrInt grant no. 88887.583508/2020-00 . ; Funding text 4: Raquel Costa was supported by the FSE and FCT under the Post-Doctoral Grant SFRH/BPD/117597/2016 [RC]. EPIUnit, ITR, and HEI-lab are supported by national funds through the Portuguese Foundation for Science and Technology , I.P., under the projects UIDB/04750/2020 , LA/P/0064/2020 , and UIDB/05380/2020 , respectively. ; Funding text 5: This publication is based upon work from COST Action 18138 - Research Innovation and Sustainable Pan-European Network in Peripartum Depression Disorder (Riseup-PPD), supported by COST (European Cooperation in Science and Technology). www.cost.eu . ; Funding text 6: Ana Osório received financial support from CAPES PROEX grant no. 0426/2021 , process no. 23038.006837/2021-73, CAPES /PrInt grant no. 88887.310343/2018-00 and MackPesquisa Fund . ; Funding text 7: Rena Bina received financial support from the Bar-Ilan Dangoor Centre for Personalized Medicine , grant no. REFU/DANGO/100. ; Funding text 8: This publication is based upon work from COST Action 18138 - Research Innovation and Sustainable Pan-European Network in Peripartum Depression Disorder (Riseup-PPD), supported by COST (European Cooperation in Science and Technology). www.cost.eu.Vera Mateus received financial support from CAPES/PrInt grant no. 88887.583508/2020-00.Ana Osório received financial support from CAPES PROEX grant no. 0426/2021, process no. 23038.006837/2021-73, CAPES/PrInt grant no. 88887.310343/2018-00 and MackPesquisa Fund.Rena Bina received financial support from the Bar-Ilan Dangoor Centre for Personalized Medicine, grant no. REFU/DANGO/100.Raquel Costa was supported by the FSE and FCT under the Post-Doctoral Grant SFRH/BPD/117597/2016 [RC]. EPIUnit, ITR, and HEI-lab are supported by national funds through the Portuguese Foundation for Science and Technology, I.P., under the projects UIDB/04750/2020, LA/P/0064/2020, and UIDB/05380/2020, respectively.This paper is part of the COST Action Riseup-PPD CA18138 and was supported by COST under COST Action Riseup-PPD CA18138. The authors would like to thank all women who participated in the survey. Sara Cruz acknowledges the Centro de Investigação em Psicologia para o Desenvolvimento (CIPD) [The Psychology for Positive Development Research Center] (UID/PSI/04375), Lusíada University North, Porto, supported by national funds through the Portuguese Foundation for Science and Technology, I.P. and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/04375/2019)