Applicability of thin-walled structures for energy-savings in steel construction

The paper discusses the use of lightweight thin-walled structures which make it possible to save resources in steel construction. The highlighted challenges that this industry face in the Russian Federation involve insufficient development of the domestic standards. A thin-walled sigma-profile element with 300 mm in a section height has been studied. The element, its design diagram and loading have been chosen taking into account the structural performance of the columns and girders involved in CFS frameworks. The paper presents analysis technique for a thin-walled profile which performs under axial compression and axial bending compression. The structures have been calculated taking into account their main feature - the initial geometric imperfections. The analysis of the changed effective characteristics and stresses in the cross-section has revealed the significant influence of the initial geometric imperfections of the profiles and location of the extra eccentricity against the element’s initial curvatures. The elastic-plastic behaviour of material occurs when the stresses in the full cross-section achieve 0.71 Ryignoring the initial geometric imperfections, and 0.58 Ry– with regard to them. The paper substantiates the need to consider unevenness of the mechanical properties of steel distributed over the cross-section of the profile. Based on the experimental data obtained, conclusions have been drawn on the necessary adaptation of the indirect method for evaluating the strength characteristics of thin-walled samples

An accelerator facility for intermediate energy proton irradiation and testing of nuclear materials

The bulk irradiation of materials with 10-30 MeV protons promises to advance the study of radiation damage for fission and fusion power plants. Intermediate energy proton beams can now be dedicated to materials irradiation within university-scale laboratories. This paper describes the first such facility, with an Ionetix ION-12SC cyclotron producing 12 MeV proton beams. Samples are mm-scale tensile specimens with thicknesses up to 300 um, mounted to a cooled beam target with control over temperature. A specialized tensile tester for radioactive specimens at high temperature (500+ {\deg}C) and/or vacuum represents the conditions in fission and fusion systems, while a digital image correlation system remotely measures strain. Overall, the facility provides university-scale irradiation and testing capability with intermediate energy protons to complement traditional in-core fission reactor and micro-scale ion irradiation. This facility demonstrates that bulk proton irradiation is a scalable and effective approach for nuclear materials research, down-selection, and qualification.Comment: Submitted to NIM B journa

Isotopic abundance of nitrogen and carbon in distant comets

The 12C14N/12C15N and 12C14N/13C14N isotopic ratios have been determined in comets C/1995 O1 (Hale-Bopp), C/2001 Q4 (NEAT) and C/2003 K4 (LINEAR) at heliocentric distances of, respectively, 2.7, 3.7 and 2.6 AU. These ratios have also been measured at r ~ 1 AU. No significant differences were found between all determinations, nor with the value obtained for other comets. If confirmed, the discrepancy between the nitrogen isotopic ratios from optical and millimeter measurements on CN and HCN would rule out HCN as a major parent of the cometary CN radicals.Comment: Accepted for publication in Astronomy ans Astrophysic

Taxing the Informal Economy: The Current State of Knowledge and Agendas for Future Research

This paper reviews the literature on taxation of the informal economy, taking stock of key debates and drawing attention to recent innovations. Conventionally, the debate on whether to tax has frequently focused on the limited revenue potential, high cost of collection, and potentially adverse impact on small firms. Recent arguments have increasingly emphasised the more indirect benefits of informal taxation in relation to economic growth, broader tax compliance, and governance. More research is needed, we argue, into the relevant costs and benefits for all, including quasi-voluntary compliance, political and administrative incentives for reform, and citizen-state bargaining over taxation

The potential risks and impact of the start of the 2015–2016 influenza season in the WHO European Region: a rapid risk assessment

Background: Countries in the World Health Organization (WHO) European Region are reporting more severe influenza activity in the 2015–2016 season compared to previous seasons. Objectives: To conduct a rapid risk assessment to provide interim information on the severity of the current influenza season. Methods: Using the WHO manual for rapid risk assessment of acute public health events and surveillance data available from Flu News Europe, an assessment of the current influenza season from 28 September 2015 (week 40/2015) up to 31 January 2016 (week 04/2016) was made compared with the four previous seasons. Results: The current influenza season started around week 51/2015 with higher influenza activity reported in Eastern Europe compared to Western Europe. There is a strong predominance of influenza A(H1N1)pdm09 compared to previous seasons, but the virus is antigenically similar to the strain included in the seasonal influenza vaccine. Compared to the 2014/2015 season, there was a rapid increase in the number of severe cases in Eastern European countries with the majority of such cases occurring among adults aged < 65 years. Conclusions: The current influenza season is characterized by an early start in Eastern European countries, with indications of a more severe season. Currently circulating influenza A(H1N1)pdm09 viruses are antigenically similar to those included in the seasonal influenza vaccine, and the vaccine is expected to be effective. Authorities should provide information to the public and health providers about the current influenza season, recommendations for the treatment of severe disease and effective public health measures to prevent influenza transmission

Applicability of thin-walled structures for energy-savings in steel construction

The paper discusses the use of lightweight thin-walled structures which make it possible to save resources in steel construction. The highlighted challenges that this industry face in the Russian Federation involve insufficient development of the domestic standards. A thin-walled sigma-profile element with 300 mm in a section height has been studied. The element, its design diagram and loading have been chosen taking into account the structural performance of the columns and girders involved in CFS frameworks. The paper presents analysis technique for a thin-walled profile which performs under axial compression and axial bending compression. The structures have been calculated taking into account their main feature - the initial geometric imperfections. The analysis of the changed effective characteristics and stresses in the cross-section has revealed the significant influence of the initial geometric imperfections of the profiles and location of the extra eccentricity against the element’s initial curvatures. The elastic-plastic behaviour of material occurs when the stresses in the full cross-section achieve 0.71 Ryignoring the initial geometric imperfections, and 0.58 Ry– with regard to them. The paper substantiates the need to consider unevenness of the mechanical properties of steel distributed over the cross-section of the profile. Based on the experimental data obtained, conclusions have been drawn on the necessary adaptation of the indirect method for evaluating the strength characteristics of thin-walled samples

Compression test results of CFS structural members

The subject of the study is the stress-strain state of a cold-formed steel structural members under axial compression. The aim is to experimentally study the behavior of a sample from a cold-formed thin-walled profile in axial compression with stress control. A mechanical method was used to test compression samples on a universal testing machine, a strain gauge method for measuring relative deformations by strain gauges with data collection in the registration unit. The processing of the test results was carried out using the methods of the theory of elasticity. As a result of the tests carried out, a qualitative picture of the deformation of the sample was obtained, the values of relative deformations at specific points of the cross sections of the sample; as a result of processing the data obtained, the main normal stresses at the points of the cross sections of the element were determined. As conclusions, an assessment of the reliability of the results obtained based on the nonlinear theory of plates is given; a conclusion is made about the inapplicability of the strain gauge method to the analysis of the behavior of thin-walled steel profiles. A promising study is the study of fields of relative deformations by non-contact optical methods

Recent foraminifera in glaciomarine sediments from three arctic fjords of Novaja Zemlja and Svalbard

Foraminifera were examined in recent