SOSORT consensus paper: school screening for scoliosis. Where are we today?

This report is the SOSORT Consensus Paper on School Screening for Scoliosis discussed at the 4th International Conference on Conservative Management of Spinal Deformities, presented by SOSORT, on May 2007. The objectives were numerous, 1) the inclusion of the existing information on the issue, 2) the analysis and discussion of the responses by the meeting attendees to the twenty six questions of the questionnaire, 3) the impact of screening on frequency of surgical treatment and of its discontinuation, 4) the reasons why these programs must be continued, 5) the evolving aim of School Screening for Scoliosis and 6) recommendations for improvement of the procedure

Preliminary electrochemical characterization of anode supported solid oxide cell (AS-SOC) produced in the Institute of Power Engineering operated in electrolysis mode (SOEC)

The article discusses the operation of solid oxide electrochemical cells (SOC) developed in the Institute of Power Engineering as prospective key components of power-to-gas systems. The fundamentals of the solid oxide cells operated as fuel cells (SOFC – solid oxide fuel cells) and electrolysers (SOEC – solid oxide fuel cells) are given. The experimental technique used for electrochemical characterization of cells is presented. The results obtained for planar cell with anodic support are given and discussed. Based on the results, the applicability of the cells in power-to-gas systems (P2G) is evaluated

Optimization of Calcium Treatment to Improve Cleanliness of Cast Steel

The effect of Ca additions on the composition, size, shape, number and distribution of inclusions in cast steel melted in a 1 ton induction furnace was studied. In order to achieve optimal inclusion modification and minimal inclusion content, several heats with different amounts and speeds of Ca wire and CaSi-wire injection in the ladle were performed. In some heats, Ar-stirring was used after Ca-wire injection. Samples collected from the furnace, ladle, and cast product were analyzed for inclusions using an automated Aspex Metals Quality Analyzer. This study summarizes the complex effects of Ca-wire treatment and Ar-stirring on inclusions in steel castings

Effects of Steel Processing on Property Variations in Eglin Steel (ES-1)

Eglin steel (ES-1) was developed by the U.S. Air Force as a cost-effective, ultra high-strength steel for military and commercial applications demanding rigorous impact toughness. The alloy contains a large tungsten addition (1 wt%) to produce a fine distribution of tungsten carbides between martensitic laths. The carbides serve as sites for dislocation pinning to produce significant work hardening and allow for high impact toughness properties. To optimize toughness, melting and refining practices are controlled to improve steel cleanliness (inclusion content) and high temperature processing treatments limit the degree of micro-segregation for better control of the carbide stability and distribution. The focus this study was to evaluate the effect of steel processing on the physical and mechanical property variations in ES-1. To better understand variations in impact properties, the inclusion and carbide content were quantified for samples produced with controlled combinations of melting, refining and heat treatment. The statistical evaluation of the carbide and inclusion content was conducted using an analytical SEM particle scanner to classify the number, size, shape, distribution and composition

User Activity Modeling Based on Markov Chain for Radio Environment Map in Cognitive Radio Networks

Представлена методика формирования расписаний перемещения и сеансов передачи данных абонентских устройств имитационной модели построения карты радиосреды для когнитивной системы сотовой связи. Методика определяет поведение абонентов как псевдослучайное на малых масштабах времени, но периодически повторяющееся в течение больших интервалов. Учитывается влияние на поведение абонентов некоторых временных параметров: типы дня, такие как рабочий, выходной, праздничный; номер дня недели; номер недели месяца. Формирование сценариев осуществляется с использованием бинарных последовательностей, получаемых с помощью цепи Маркова, и генератора импульсного шума для изменения состояния абонентов. Программная реализация модели выполнена в программной среде MatLab, представлены результаты исследований, которые подтверждают корректность работы модели и возможность использования предложенного подхода для формирования карты радиосреды

Modeling and Simulation of Mass Flow of Steel Plate/Slab during Hot Rolling

The ability to predict mass flow behavior during hot rolling is essential to product quality. In this study, viscoplastic models of the steels from SSAB and U.S. Steel were developed based on experimental stress-strain curves. A three-dimensional nonlinear finite element model was built to simulate a reverse plate hot rolling and a hot strip rolling process. For plate rolling, a seven pass schedule was simulated. The plastic strain distributions during rolling were investigated. The results show that the surface of the plate has larger plastic strain than the center. In the case of hot strip rolling, the simulation predicts that material flows from the sides to the top and bottom surfaces during edging. The top and bottom surfaces were then rolled flat. Details of the material flow and strain distributions during edging and rolling are presented in this paper