Normal and tangential behaviour of dry joints in refractory masonry

Industrial vessels used in high temperature processes of steel and cement production are protected by refractory linings built with mortarless joints. These dry joints, formed by stacked bricks have a crucial importance on the mechanical behaviour of the lining. The stiffness and consequently the stresses generated by thermal expansion are reduced due to the joints. The present article presents the results of experimental and numerical tests on the thermomechanical behaviour of these joints. The compressive strength of the brick was assessed at ambient and high temperatures and a statistical analysis of the distribution of the bricks’ shape imperfections was carried out. Several studies were carried out on the normal behaviour of the joints: classical joint closure test; bed joint closing action in a masonry wallet measured with a DIC; effects of brick’s height imperfections on its loadbearing capacity; effects of brick’s height imperfections on the wall’s behaviour at ambient and high temperatures and a comparison between the bed and head joints behaviour. To characterize the joint’s tangential behaviour at high temperatures a novel device was developed and presented.The authors would like to thank the support of European Commission under the framework of Marie Sklodowska-Curie Actions Innovative Training Networks, project ATHOR -Advanced THermomechanical multiscale mOdelling of Refractory linings 764987 Grant

Welche Macht darf es denn Sein? Tracing ‘Power’ in German Foreign Policy Discourse

The relationship between ‘Germany’ and ‘power’ remains a sensitive issue. While observers tend to agree that Germany has regained the status of the most powerful country in Europe, there is debate whether that is to be welcomed or whether that is a problem. Underpinning this debate are views, both within Germany and amongst its neighbours, regarding the kind of power Germany has, or should (not) have. Against this backdrop, the article reviews the dominant role conceptions used in the expert discourse on German foreign policy since the Cold War that depict Germany as a particular type of ‘power’. Specifically, we sketch the evolution of three prominent conceptions (constrained power, civilian power, hegemonic power) and the recent emergence of a new one (shaping power). The article discusses how these labels have emerged to give meaning to Germany’s position in international relations, points to their normative and political function, and to the limited ability of such role images to tell us much about how Germany actually exercises power

Obeticholic acid for the treatment of non-alcoholic steatohepatitis: interim analysis from a multicentre, randomised, placebo-controlled phase 3 trial

Background Non-alcoholic steatohepatitis (NASH) is a common type of chronic liver disease that can lead to cirrhosis. Obeticholic acid, a farnesoid X receptor agonist, has been shown to improve the histological features of NASH. Here we report results from a planned interim analysis of an ongoing, phase 3 study of obeticholic acid for NASH. Methods In this multicentre, randomised, double-blind, placebo-controlled study, adult patients with definite NASH,non-alcoholic fatty liver disease (NAFLD) activity score of at least 4, and fibrosis stages F2–F3, or F1 with at least oneaccompanying comorbidity, were randomly assigned using an interactive web response system in a 1:1:1 ratio to receive oral placebo, obeticholic acid 10 mg, or obeticholic acid 25 mg daily. Patients were excluded if cirrhosis, other chronic liver disease, elevated alcohol consumption, or confounding conditions were present. The primary endpointsfor the month-18 interim analysis were fibrosis improvement (≥1 stage) with no worsening of NASH, or NASH resolution with no worsening of fibrosis, with the study considered successful if either primary endpoint was met. Primary analyses were done by intention to treat, in patients with fibrosis stage F2–F3 who received at least one dose of treatment and reached, or would have reached, the month 18 visit by the prespecified interim analysis cutoff date. The study also evaluated other histological and biochemical markers of NASH and fibrosis, and safety. This study is ongoing, and registered with ClinicalTrials.gov, NCT02548351, and EudraCT, 20150-025601-6. Findings Between Dec 9, 2015, and Oct 26, 2018, 1968 patients with stage F1–F3 fibrosis were enrolled and received at least one dose of study treatment; 931 patients with stage F2–F3 fibrosis were included in the primary analysis (311 in the placebo group, 312 in the obeticholic acid 10 mg group, and 308 in the obeticholic acid 25 mg group). The fibrosis improvement endpoint was achieved by 37 (12%) patients in the placebo group, 55 (18%) in the obeticholic acid 10 mg group (p=0·045), and 71 (23%) in the obeticholic acid 25 mg group (p=0·0002). The NASH resolution endpoint was not met (25 [8%] patients in the placebo group, 35 [11%] in the obeticholic acid 10 mg group [p=0·18], and 36 [12%] in the obeticholic acid 25 mg group [p=0·13]). In the safety population (1968 patients with fibrosis stages F1–F3), the most common adverse event was pruritus (123 [19%] in the placebo group, 183 [28%] in the obeticholic acid 10 mg group, and 336 [51%] in the obeticholic acid 25 mg group); incidence was generally mild to moderate in severity. The overall safety profile was similar to that in previous studies, and incidence of serious adverse events was similar across treatment groups (75 [11%] patients in the placebo group, 72 [11%] in the obeticholic acid 10 mg group, and 93 [14%] in the obeticholic acid 25 mg group). Interpretation Obeticholic acid 25 mg significantly improved fibrosis and key components of NASH disease activity among patients with NASH. The results from this planned interim analysis show clinically significant histological improvement that is reasonably likely to predict clinical benefit. This study is ongoing to assess clinical outcomes

Thermomechanical behaviour of refractory dry-stacked masonry walls under uniaxial compression

Vessels used in industrial high temperature processes of steel and cement production are protected by refractory linings built with dry-stacked masonry, which plays a crucial role on the overall behaviour of the vessels. This paper presents the results of an experimental and numerical research on dry-joint refractory masonry subjected to uniaxial compression. Its main purpose is to fully characterize the masonry walls at different temperatures and different loading conditions. Several aspects that may influence the behaviour of these walls have been tested, namely the loadbearing capacity, the behaviour under cyclic loading and the restrained thermal elongation. The experimental results allowed to identify the effects of the stress concentrations caused by brick’s height imperfections in the mechanical behaviour of the bricks and in the loadbearing capacity of the specimens, the evolution of the wall’s Young’s modulus with the load application, the developed crack patterns and the mechanical behaviour of the samples at ambient and high temperatures. Numerical models were also developed to simulate the behaviour of the walls under different testing conditions and a good agreement with the experimental results was obtained. The concrete damaged plasticity model, using a micro-modelling approach, proved to be suitable for representing the behaviour of these walls at ambient and high temperatures.This work was supported by the funding scheme of the European Commission, Marie Skodowska-Curie Actions Innovative Training Networks in the frame of the project ATHOR - Advanced THermomechanical multiscale mOdelling of Refractory linings 764987 Grant

Experimental characterization of the nonlinear thermomechanical behaviour of refractory masonry with dry joints

International audienceRefractory linings can withstand severe working conditions and are widely used for the linings of many high temperature applications, such as steel ladles. Some of these linings are built with dry joints. These structures undergo very complex responses in service conditions, making the prediction of its behaviour a challenging task. To develop robust numerical prediction tools, experimental validation is necessary. The present paper gathers a considerable database on the mechanical and thermomechanical characterization of refractory masonry with dry joints (up to 1500 °C). The test setups, measurement techniques, specimens, test procedures, and results of the large-scale experimental campaign are presented. The results of the tests help in understanding the complex thermomechanical behaviour of refractory linings. Aspect such as joints closure and reopening, dimensional and shape tolerances of the bricks, creep and stress relaxation are investigated. The results of these tests are essential for developing, calibrating, and validating efficient numerical models for the design and optimization of refractory masonry linings

Epidemiology and causes of death in a Swedish cohort of patients with autoimmune hepatitis

Background: Epidemiological studies of autoimmune hepatitis (AIH) show varying figures on prevalence and incidence, and data on the long-term prognosis are scarce. Objective To investigate the epidemiology, long-term prognosis and causes of death in a Swedish AIH cohort. Material and methods: Data collected from 634 AIH patients were matched to the Cause of Death Registry, and survival analyses were made. Prevalence and incidence were calculated for university hospitals with full coverage of cases and compared to the County of Västerbotten in Northern Sweden. Results: AIH point prevalence was 17.3/100,000 inhabitants in 2009, and the yearly incidence 1990–2009 was 1.2/100,000 inhabitants and year. The time between diagnosis and end of follow-up, liver transplantation or death was in median 11.3 years (range 0–51.5 years). Men were diagnosed earlier (p < .001) and died younger than women (p = .002). No gender differences were found concerning transplant-free, overall survival and liver-related death. Cirrhosis at diagnosis was linked to an inferior survival (p < .001). Liver-related death was the most common cause of death (32.7%). The relative survival started to diverge from the general population 4 years after diagnosis but a distinct decline was not observed until after more than 10 years. Conclusions: Long-term survival was reduced in patients with AIH. No gender difference regarding prognosis was seen but men died younger, probably as a result of earlier onset of disease. Cirrhosis at diagnosis was a risk factor for poor prognosis and the overall risk of liver-related death was increased

Histological improvement of liver fibrosis in well-treated patients with autoimmune hepatitis : a cohort study

Objectives Autoimmune hepatitis (AIH) is a chronic autoimmune liver disease that if left untreated may lead to the development of cirrhosis. Previous studies on AIH patients have suggested that fibrosis and even cirrhosis can be reversed by medical treatment. The aim of this study was to evaluate the efficacy of medical treatment for protection of developing fibrosis and cirrhosis. Methods Two hundred fifty-eight liver biopsies from 101 patients (72 women, 29 men) were analysed by a single pathologist and classified accordingly to the Ishak grading (inflammation) and staging (fibrosis) system. Liver histology was stratified according to the temporal changes of fibrosis stage (increased, decreased or stable), and groups were compared. Results Complete or partial response to medical treatment was 94.9%. Reduction of fibrosis stage from the first to the last biopsy was seen in 63 patients (62.4%). We found an association between a reduction in fibrosis stage and continuous glucocorticoid medication, as well as lowered scores of inflammation at last biopsy. Twenty-one patients had cirrhosis (Ishak stage 6) at least in one of the previous biopsies, but only five patients at the last biopsy. Conclusions Histological improvement is common in AIH patients that respond to medical treatment, and a reduction or stabilization of fibrosis stage occurs in about 2/3 of such patients.Originally included in thesis in manuscript form </p