Effect of Weld Schedule on the Residual Stress Distribution of Boron Steel Spot Welds

Press-hardened boron steel has been utilized in anti-intrusion systems in automobiles, providing high strength and weight-saving potential through gage reduction. Boron steel spot welds exhibit a soft heat-affected zone which is surrounded by a hard nugget and outlying base material. This soft zone reduces the strength of the weld and makes it susceptible to failure. Additionally, different welding regimes lead to significantly different hardness distributions, making failure prediction difficult. Boron steel sheets, welded with fixed and adaptive schedules, were characterized. These are the first experimentally determined residual stress distributions for boron steel resistance spot welds which have been reported. Residual strains were measured using neutron diffraction, and the hardness distributions were measured on the same welds. Additionally, similar measurements were performed on spot welded DP600 steel as a reference material. A correspondence between residual stress and hardness profiles was observed for all welds. A significant difference in material properties was observed between the fixed schedule and adaptively welded boron steel samples, which could potentially lead to a difference in failure loads between the two boron steel welds

Characterization of Loading Responses and Failure Loci of a Boron Steel Spot Weld

Boron steel, classed as an ultra high-strength steel (UHSS), has been utilized in anti-intrusion systems in automobiles, providing high strength and weight-saving potential through gage reduction. UHSS spot welds exhibit unique hardness distributions, with a hard nugget and outlying base material, but with a soft heat-affected zone in-between these regions. This soft zone reduces the strength of the weld and makes it susceptible to failure. Due to the interaction of various weld zones that occurs during loading, there is a need to characterize the loading response of the weld for accurate failure predictions. The loading response of certain weld zones, as well as failure loci, was obtained through physical simulation of the welding process. The results showed a significant difference in mechanical behavior through the weld length. An important result is that instrumented indentation was shown to be a valid, quantitative method for verifying the accuracy with which weld microstructure has been recreated with regard to the target weld microstructure

'HepCheck Dublin': An Intensified Hepatitis C Screening Programme in a Homeless Population Demonstrates the Need for Alternative Models of Care

Background: Hepatitis C virus (HCV) is one of the main causes of chronic liver disease worldwide. Prevalence of HCV in homeless populations ranges from 3.9% to 36.2%. The HepCheck study sought to investigate and establish the characterisation of HCV burden among individuals who attended an intensified screening programme for HCV in homeless services in Dublin, Ireland. Methods: The HepCheck study was conducted as part of a larger European wide initiative called HepCare Europe. The study consisted of three phases; 1) all subjects completed a short survey and were offered a rapid oral HCV test; 2) a convenience sample of HCV positive participants from phase 1 were selected to complete a survey on health and social risk factors and 3) subjects were tracked along the referral pathway to identify whether they were referred to a specialist clinic, attended the specialist clinic, were assessed for cirrhosis by transient elastography (Fibroscan) and were treated for HCV. Results: 597 individuals were offered HCV screening, 73% were male and 63% reported having had a previous HCV screening. We screened 538 (90%) of those offered screening, with 37% testing positive. Among those who tested positive, 112 (56%) were ‘new positives’ and 44% were ‘known positives’. Undiagnosed HCV was prevalent in 19% of the study sample. Active past 30-day drug use was common, along with attendance for drug treatment. Unstable accommodation was the most common barrier to attending specialist appointments and accessing treatment. Depression and anxiety, dental problems and respiratory conditions were common reported health problems. 46 subjects were referred to specialised services and two subjects completed HCV treatment. Conclusions: This study demonstrates that the current hospital-based model of care is inadequate in addressing the specific needs of a homeless population and emphasises the need for a community-based treatment approach. Findings are intended to inform HepCare Europe in their development of a community-based model of care in order to engage with homeless individuals with multiple co-morbidities including substance abuse, who are affected by or infected with HCV

Integrated Hepatitis C Care for People Who Inject Drugs (Heplink): Protocol for a Feasibility Study in Primary Care (Preprint)

Background: Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and death. Drug use remains the significant cause of new infections in the European Union, with estimates of HCV antibody prevalence among people who inject drugs ranging from 5% to 90% in 29 European countries. In Ireland and the European Union, primary care is a key area to focus efforts to enhance HCV diagnosis and treatment among people who inject drugs. Objective: The Heplink study aims to improve HCV care outcomes among opiate substitution therapy (OST) patients in general practice by developing an integrated model of HCV care and evaluating its feasibility, acceptability, and likely efficacy. Methods: The integrated model of care comprises education of community practitioners, outreach of an HCV-trained nurse into general practitioner (GP) practices, and enhanced access of patients to community-based evaluation of their HCV disease (including a novel approach to diagnosis, that is, Echosens FibroScan Mini 430). A total of 24 OST-prescribing GP practices were recruited from the professional networks and databases of members of the research consortium. Patients were eligible if they are aged ≥18 years, on OST, and attend the practice for any reason during the recruitment period. Baseline data on HCV care processes and outcomes were extracted from the clinical records of participating patients. Results: This study is ongoing and has the potential to make an important impact on patient care and provide high-quality evidence to help GPs make important decisions on HCV testing and onward referral. Conclusions: A substantial proportion of HCV-positive patients on OST in general practice are not engaged with specialist hospital services but qualify for direct-acting antiviral drugs treatment. The Heplink model has the potential to reduce HCV-related morbidity and mortality. Registered Report Identifier: RR1-10.2196/904

Stellar coronal astronomy - a review

Coronal astronomy is by now a fairly mature discipline, with a quarter century having gone by since the detection of the first stellar X-ray coronal source (Capella), and having benefitted from a series of major orbiting observing facilities. Several observational characteristics of coronal X-ray and EUV emission have been solidly established through extensive observations, and are by now common, almost text-book, knowledge. At the same time the implications of coronal astronomy for broader astrophysical questions (e.g. Galactic structure, stellar formation, stellar structure, etc.) have become appreciated. The interpretation of stellar coronal properties is however still often open to debate, and will need qualitatively new observational data to book further progress. In the present review we try to recapitulate our view on the status of the field at the beginning of a new era, in which the high sensitivity and the high spectral resolution provided by Chandra and XMM-Newton will address new questions which were not accessible before.Comment: Space Science Reviews, in press, 132 pages (full paper available at ftp://astro.esa.int/pub/ffavata/Papers/ssr-preprint.pdf

Recommendations for Transitioning Young People with Primary Immunodeficiency Disorders and Autoinflammatory Diseases to Adult Care

\ua9 The Author(s) 2024.Purpose: Significant improvements in the prognosis for young patients with Primary Immunodeficiency Diseases (PID) and Autoinflammatory Disorders (AID), which together make up the majority of Inborn Errors of Immunity (IEI), have resulted in the need for optimisation of transition and transfer of care to adult services. Effective transition is crucial to improve health outcomes and treatment compliance among patients. Evaluations of existing transition programmes in European health centres identified the absence of disease-specific transition guidelines for PID and AID, as a challenge to the transition process. This research aimed to establish expert consensus statements for the transition of young patients with PID and AID to adult services. Methods: This project used the Delphi method to establish mutual agreement for the proposed recommendations. A draft set of statements was developed following a literature review of existing transition programmes. Then the ERN RITA Transition Working Group convened to review the drafted recommendations and develop them into a survey. This survey was circulated among healthcare professionals to determine consensus using a five-point Likert scale, with the level of agreement set to 80% or greater. Statements that did not reach consensus were revised by the Working Group and recirculated among respondents. Results: The initial survey received 93 responses from 68 centres across 23 countries, while the following survey outlining revised recommendations received 66 responses. The respondents agreed upon recommendations detailing the structure and administration of transition programmes, collaborative working with social systems, and contraindications to transfer of care. Conclusion: This paper sets out a comprehensive set of recommendations to optimise transitional care for PID and AID