Finite element analysis of hydrogen retention in ITER plasma facing components using FESTIM

The behaviour of hydrogen isotopes in ITER monoblocks was studied using the code FESTIM (Finite Element Simulation of Tritium In Materials) which is introduced in this publication. FESTIM has been validated by reproducing experimental data and the Method of Manufactured Solutions was used for analytical verification. Following relevant plasma scenarios, both transient heat transfer and hydrogen isotopes (HIs) diffusion have been simulated in order to assess HIs retention in monoblocks. Relevant materials properties have been used. Each plasma cycle is composed of a current ramp up, a current plateau, a current ramp down and a resting phase before the following shot. 100 cycles are simulated. The total HIs inventory in the tokamak during resting phases reaches 1.8 x 10(-3) mgwhereas during the implantation phases it keeps increasing as a power law of time. Particle flux on the cooling channel of the monoblock is also computed. The breakthrough time is estimated to be t = 1 x 10(5) s which corresponds to 24 cycles. Relevance of 2D modelling has been demonstrated by comparing the total HIs inventory obtained by 2D and 1D simulations. Using 1D simulations, a relative error is observed compared to 2D simulations which can reach -25% during the resting phase. The error during implantation phases keeps increasing.Peer reviewe

New rate equation model to describe the stabilization of displacement damage by hydrogen atoms during ion irradiation in tungsten

The effect of deuterium (D) presence on the amount of displacement damage created in tungsten (W) during high-energy W-ion irradiation is investigated. For this purpose, we have performed modelling of experimental results where W was sequentially or simultaneously irradiated by 10.8 MeV W ions and exposed to 300 eV D ions. A novel displacement damage creation and stabilization model was newly developed and introduced into the MHIMS-Reservoir (Migration of Hydrogen Isotopes in MaterialS) code. It employs macroscopic rate equations (MREs) for solving the evolution of solute and trapped D concentrations in the material. The new displacement damage creation and stabilization model is based on spontaneous recombination of Frenkel pairs and stabilization of defects that are occupied by D atoms. By using the new model, we could successfully replicate the measured D depth profiles and D thermal desorption data, where a higher defect concentration was observed when D was present during W irradiation as compared to when no D was present. For this we utilized parameters, which include the number of distinct defect types, the de-trapping energies of their fill-levels, their saturation concentrations and their probability for stabilization if they contain a D during the W-ion irradiation. To successfully replicate the experimental results three distinct defect types were needed with several fill-levels. By comparing the de-trapping energies of the defect fill-levels with data available from the literature, the defect types were identified as single-vacancies, small vacancy clusters and large vacancy clusters. The effect of D presence was found to be largest in single vacancies as its concentration increased by about a factor of three, while the concentration of small vacancy clusters increased by about a factor of two. Large vacancy clusters were found to be largely unaffected as they showed very little increase in concentration when D was presentPeer reviewe

The burnout syndrome in palliative home care workers: the role of coping strategies and metacognitive beliefs

Healthcare professionals are daily confronted with events involving the suffering of others, which are likely to generate highly negative and stressful emotions. In palliative care the emotional commitment is exacerbated by the constant confrontation with the theme of suffering and death. The failure to successfully down-regulate negative emotions is a key risk factor for a severe form of discomfort, known as burnout syndrome. Burnout is a psychological state of exhaustion, related to stress at work. Maslach (1996) describes it as a psychological syndrome of emotional exhaustion, depersonalization, and reduced personal accomplishment. Recent studies have shown that healthcare worker coping strategies may function either as a risk or aprotective factor for the development of distress and emotional problems. Furthermore, other studies highlighted the role of the dimensions of metacognition as vulnerability factors in predicting the development of psychological symptoms. The aim of this study is to examine and assess the relationships between burnout, coping strategies and metacognitive beliefs in workers involved in home palliative care. The hypothesis of the present work is that the appropriate use of positive and flexible coping strategies and functional metacognitive beliefs may relate to the management of distress and emotional problems. A group of operators working in a team of Integrated Home Palliative Care participated in the research.The study was based on a protocol including the Italian version of MCQ-30, used to assess a range of metacognitive beliefs and processes relevant to vulnerability and maintenance of emotional disorders; the Brief Cope (BC) to survey coping strategies; Maslach Burnout Inventory (MBI) to measure burnout. The questionnaire includes a socio-demographical section. The results show the presence of a statistically significant correlation between the variables investigated

Variability of Forebrain Commissures in Callosal Agenesis: A Prenatal MR Imaging Study

BACKGROUND AND PURPOSE: Agenesis of the corpus callosum, even when isolated, may be characterized by anatomic variability. The aim of this study was to describe the types of other forebrain commissures in a large cohort of randomly enrolled fetuses with apparently isolated agenesis of the corpus callosum at prenatal MR imaging. MATERIALS AND METHODS: All fetuses with apparent isolated agenesis of the corpus callosum undergoing prenatal MR imaging from 2004 to 2014, were evaluated for the presence of the anterior or a vestigial hippocampal commissure assessed in consensus by 2 pediatric neuroradiologists. RESULTS: Overall, 62 cases of agenesis of the corpus callosum were retrieved from our data base. In 3/62 fetuses (4.8%), no forebrain commissure was visible at prenatal MR imaging, 23/62 fetuses (37.1%) presented with only the anterior commissure, and 20/62 fetuses (32.3%) showed both the anterior commissure and a residual vestigial hippocampal commissure, whereas in the remaining 16/62 fetuses (25.8%), a hybrid structure merging a residual vestigial hippocampal commissure and a rudiment of the corpus callosum body was detectable. Postnatal MR imaging, when available, confirmed prenatal forebrain commissure findings. CONCLUSIONS: Most fetuses with apparent isolated agenesis of the corpus callosum showed at least 1 forebrain commissure at prenatal MR imaging, and approximately half of fetuses also had a second commissure: a vestigial hippocampal commissure or a hybrid made of a hippocampal commissure and a rudimentary corpus callosum body. Whether such variability is the result of different genotypes and whether it may have any impact on the long-term neurodevelopmental outcome remains to be assessed. AC : anterior commissure ACC : agenesis of the corpus callosum CC : corpus callosum GA : gestational age HC : hippocampal commissure HS : hybrid structur

Relação entre polimorfismos no gene da leptina, ganho de peso e concentração sérica de leptina em bovinos de corte.

O objetivo do trabalho é estabelecer a relação de polimorfismos no gene da leptina com a quantidade de leptina sérica e ganho de peso durante o confinamento, visando a utilização de dados obtidos em programas de seleção animal. Os bovinos confinados utilizados na pesquisa serão provenientes da Fazenda Tuju Puitan. Serão objetos da pesquisa 100 animais com idade média de 12 meses

The Ecotoxicology of Microbial Insecticides and Their Toxins in Genetically Modified Crops: An Overview.

Abstract: The use of microbial insecticides and their toxins in biological control and transgenic plants has increased their presence in the environment. Although they are natural products, the main concerns are related to the potential impacts on the environment and human health. Several assays have been performed worldwide to investigate the toxicity or adverse effects of these microbial products or their individual toxins. This overview examines the published data concerning the knowledge obtained about the ecotoxicity and environmental risks of these natural pesticides. The data presented show that many results are difficult to compare due to the diversity of measurement units used in the different research data. Even so, the products and toxins tested present low toxicity and low risk when compared to the concentrations used for pesticide purposes. Complementary studies should be carried out to assess possible effects on human health

Acute toxicity and cytotoxicity of Bacillus thuringiensis and Bacillus sphaericus strains on fish and mouse bone marrow.

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