THERMODYNAMIC MODELLING TO SUPPORT PRODUCTION OF HIGH NITROGEN STEELS BY DIFFERENT PROCESSES

High Nitrogen Stainless Steel (HNSS) have a high potential for several applications due to their attractive properties: by varying the range of composition of the steel, metallurgists are exploying these materials for many important applications. Actually, there are some processing routes available: the most part of the world production of HNSS is made by electric plus AOD for low-medium content of N and by PESR for high content of nitrogen The main criticality that can be encountered during the solidification of high nitrogen steels is the formation of gas bubbles due to supersaturation of nitrogen in the melt, that induces porosity in the final macrostructure. Therefore, tools for prediction of solidification behaviour of HNSS under different casting conditions, are required to prevent defectiveness due to pores in the final products. In the present work, a simple microsegregation model interfaced with Thermocalc has been implemented, which allows to predict the conditions for gas nucleation during solidification. This model has been validated by comparison with experimental results of solidification of different HNSS grades in conditions variable from vacuum to high pressure, and represents an useful tool to support HNSS industrial production

National approaches to the vaccination of recently arrived migrants in Europe : A comparative policy analysis across 32 European countries

Funding Information: However, current approaches to the vaccination of migrants have not been well documented to date, and it is acknowledged that there are additional challenges in ensuring equitable access to vaccines in diverse and mobile migrant populations [9,11]. The ongoing refugee crisis has facilitated renewed dialogue around approaches to the screening and vaccination of recently arrived migrants for infectious diseases. The World Health Organization (WHO), United Nations High Commissioner for Refugees, and the United Nations Children's Fund recommended in 2015 that migrants in the WHO European Region should be vaccinated soon after arrival in accordance with the immunisation schedule of the receiving country in which they intend to stay for more than a week [11], and the European Centre for Disease Prevention and Control (ECDC) is currently developing guidance on approaches to vaccine-preventable diseases in newly arrived migrants [12]. However, there has to date been no comprehensive examination of what policies or guidelines are currently implemented across Europe, or how they compare across countries. In order to facilitate the harmonisation of vaccination policies across Europe and identify best practice, a clear understanding of the different policies and of the key gaps or inconsistencies in such policies is needed [13,14]. We therefore did a comparative analysis of policies and guidelines in EU/EEA countries and Switzerland relating to the provision of vaccinations to recently arrived migrants to identify common approached.This research was funded by the European Society of Clinical Microbiology and Infectious Diseases through the ESCMID Study Group for Infections in Travellers and Migrants (ESGITM). LBN, SH, and JSF receive funding from the UK National Institute for Health Research Imperial Biomedical Research Centre, the Imperial College Healthcare Charity, and the Wellcome Trust (Grant number 209993/Z/17/Z). Funding Information: This research was funded by the European Society of Clinical Microbiology and Infectious Diseases through the ESCMID Study Group for Infections in Travellers and Migrants (ESGITM). LBN, SH, and JSF receive funding from the UK National Institute for Health Research Imperial Biomedical Research Centre , the Imperial College Healthcare Charity , and the Wellcome Trust (Grant number 209993/Z/17/Z ). Publisher Copyright: © 2018 The AuthorsBackground: Migrants may be underimmunised and at higher risk of vaccine-preventable diseases, yet there has been no comprehensive examination of what policies are currently implemented across Europe targeting child and adult migrants. We analysed vaccination policies for migrants in 32 EU/EEA countries and Switzerland. Methods: Using framework analysis, we did a comparative analysis of national policies and guidelines pertaining to vaccination in recently arrived migrants through a systematic guideline and literature review and by approaching national experts. Results: Six (18.8%) of 32 countries had comprehensive policies specific to the vaccination of migrants (two focused only on child migrants, four on both adults and children). Nineteen (59.4%) countries applied their national vaccination schedule for migrant vaccinations, predominantly focusing on children; and five (15.6%) countries had circulated additional migrant-specific resources to relevant health-care providers. In six (18.8%) countries, policies on migrant vaccination focused on outbreak-specific vaccines only. In ten (31.3%) countries, policies focused on priority vaccinations, with polio being the vaccine most commonly administered and heterogeneity noted in vaccines recommended to adults, adolescents, and children. Eighteen (56.3%) countries recommended that an individual should be considered as unvaccinated where vaccination records were missing, and vaccines re-administered. Nine (28.1%) countries reported that specific vaccinations were mandatory. Conclusion: There is considerable variation in policies across Europe regarding approaches to vaccination in adult and child migrants, and a lack of clarity on optimum ways forward, what vaccines to offer, with a need for robust research in this area. More emphasis must be placed on ensuring migrant-specific guidance is disseminated to front-line healthcare professionals to improve vaccine delivery and uptake in diverse migration populations across the region.publishersversionPeer reviewe

A cohort study to evaluate persistence of hepatitis B immunogenicity after administration of hexavalent vaccines

<p>Abstract</p> <p>Background</p> <p>In 2001, two hexavalent vaccines were licensed in Italy (Hexavac^®, Infanrix Hexa^®), and since 2002 were extensively used for primary immunization in the first year of life (at 3, 5, 11/12 months of age). In 2005, the market authorization of Hexavac^®was precautionary suspended by EMEA, because of doubts on long-term protection against hepatitis B virus. The objectives of this study were to evaluate the persistence of antibodies to anti-HBs, in children in the third year of life, and to investigate the response to a booster dose of hepatitis B vaccine.</p> <p>Methods</p> <p>Participant children were enrolled concomitantly with the offering of anti-polio booster dose, in the third year of life. Anti-HBs titers were determined on capillary blood samples. A booster dose of hepatitis B vaccine was administered to children with anti-HBs titers < 10 mIU/ml, with the monovalent precursor product of the previously received hexavalent vaccine. HBsAb titers were tested again one month after the booster.</p> <p>Results</p> <p>Sera from 113 children previously vaccinated with Hexavac^®, and from 124 vaccinated with Infanrix Hexa^®were tested for anti-HBs. Titers were ≥ 10 mIU/ml in 69% and 96% (p < 0,0001) respectively. The proportion of children with titers ≥ 100 mIU/ml did also significantly differ among groups (27% and 78%; p < 0,0001).</p> <p>Post-booster, 93% of children achieved titers ≥ 10 mIU/ml, with no significant difference by vaccine group.</p> <p>Discussion</p> <p>Fifteen months after third dose administration, a significant difference in anti-HBs titers was noted in the two vaccine groups considered. Monovalent hepatitis B vaccine administration in 3-year old children induced a proper booster response, confirming that immunologic memory persists in children with anti-HBs titers < 10 mIU/ml. However, long-term persistence of HBV protection after hexavalent vaccines administration should be further evaluated over time.</p

Migrant and refugee populations: a public health and policy perspective on a continuing global crisis.

The 2015-2017 global migratory crisis saw unprecedented numbers of people on the move and tremendous diversity in terms of age, gender and medical requirements. This article focuses on key emerging public health issues around migrant populations and their interactions with host populations. Basic needs and rights of migrants and refugees are not always respected in regard to article 25 of the Universal Declaration of Human Rights and article 23 of the Refugee Convention. These are populations with varying degrees of vulnerability and needs in terms of protection, security, rights, and access to healthcare. Their health status, initially conditioned by the situation at the point of origin, is often jeopardised by adverse conditions along migratory paths and in intermediate and final destination countries. Due to their condition, forcibly displaced migrants and refugees face a triple burden of non-communicable diseases, infectious diseases, and mental health issues. There are specific challenges regarding chronic infectious and neglected tropical diseases, for which awareness in host countries is imperative. Health risks in terms of susceptibility to, and dissemination of, infectious diseases are not unidirectional. The response, including the humanitarian effort, whose aim is to guarantee access to basic needs (food, water and sanitation, healthcare), is gripped with numerous challenges. Evaluation of current policy shows insufficiency regarding the provision of basic needs to migrant populations, even in the countries that do the most. Governments around the world need to rise to the occasion and adopt policies that guarantee universal health coverage, for migrants and refugees, as well as host populations, in accordance with the UN Sustainable Development Goals. An expert consultation was carried out in the form of a pre-conference workshop during the 4th International Conference on Prevention and Infection Control (ICPIC) in Geneva, Switzerland, on 20 June 2017, the United Nations World Refugee Day

Elastic and anelastic behaviour of PWA 1483 single crystal super alloy

The PWA 1483 single crystal super alloy, a material of interest for applications in advanced gas turbines of electrical power plants, has been investigated by internal friction and dynamic modulus measurements in the temperature range 25-800 °C. The tests have been carried out on bar-shaped samples (50 x 6 x 0.7 mm3 ) vibrating in flexural mode with resonance frequency of ∼ 350 Hz. To assess the structural stability, each sample has been subjected to several successive measurement cycles. During heating all the samples exhibit a maxima of internal friction at ∼ 350 °C, which is accompanied by an abrupt increase of dynamic modulus. The phenomenon is observed at slightly higher temperatures for higher heating rates. At the end of each cycle (when the sample has been cooled down to room temperature) the dynamic modulus is a little higher than the original value. Experimental results can be explained by assuming the presence of unstable dislocation structures which evolve after heating. Anelasticity phenomena observed by us have been ascribed to change of dislocation density and mean distance between pinning points of dislocation segments

Elastic and anelastic behaviour of PWA 1483 single crystal super alloy

The PWA 1483 single crystal super alloy, a material of interest for applications in advanced gas turbines of electrical power plants, has been investigated by internal friction and dynamic modulus measurements in the temperature range 25-800 °C. The tests have been carried out on bar-shaped samples (50 x 6 x 0.7 mm3 ) vibrating in flexural mode with resonance frequency of ∼ 350 Hz. To assess the structural stability, each sample has been subjected to several successive measurement cycles. During heating all the samples exhibit a maxima of internal friction at ∼ 350 °C, which is accompanied by an abrupt increase of dynamic modulus. The phenomenon is observed at slightly higher temperatures for higher heating rates. At the end of each cycle (when the sample has been cooled down to room temperature) the dynamic modulus is a little higher than the original value. Experimental results can be explained by assuming the presence of unstable dislocation structures which evolve after heating. Anelasticity phenomena observed by us have been ascribed to change of dislocation density and mean distance between pinning points of dislocation segments