Nonmetallic inclusion modification and its effect on the final properties of a linepipe steel

Five linepipe type steels were produced in order to study the effect of calcium and magnesium injection on their final properties. Two of these steels were at the extremes of the sulphide range i.e. 0.003 and 0.017% sulphur with no injection attempted; thereby, providing standards to compare with the injected steels. The oxygen level varied from 21 to 63 p.p.m. The cast ingots were controlled-rolled and isothermally rolled in order to study the deformation characteristics of the residual non-metallic inclusions. The structure and cleanliness of these steels was evaluated metallographically using the light microscope, SEM, and image analysis and the results related to their Charpy toughness and HIC resistance. Increasing sulphur levels decreased final properties of the steel. In the untreated state, with as little as 0.003% sulphur, test orientation was highly influential. Modification of sulphur bearing steels was achieved with low modifying element to sulphur ratios provided that the oxygen content was very low. Injection of calcium into steel caused interaction with oxide and sulphide inclusions which was biased toward oxide reduction relative to sulphur removal. Magnesium again reduced oxides and appeared to be linked with aluminia containing inclusions in the final product. It produced improved toughness values relative to a similar sulphur containing calcium treated steel. The results of this work could be extended to establish the mechanism of inclusion modification with magnesium additions to sulphur bearing steels.

Common variance in amplitude envelope perception tasks and their impact on phoneme duration perception and reading and spelling in Finnish children with reading disabilities

Our goal was to investigate auditory and speech perception abilities of children with and without reading disability (RD) and associations between auditory, speech perception, reading, and spelling skills. Participants were 9-year-old, Finnish-speaking children with RD (N = 30) and typically reading children (N = 30). Results showed significant group differences between the groups in phoneme duration discrimination but not in perception of amplitude modulation and rise time. Correlations among rise time discrimination, phoneme duration, and spelling accuracy were found for children with RD. Those children with poor rise time discrimination were also poor in phoneme duration discrimination and in spelling. Results suggest that auditory processing abilities could, at least in some children, affect speech perception skills, which in turn would lead to phonological processing deficits and dyslexia.

Servitization within manufacturing:exploring the provision of advanced services and their impact on vertical integration

Purpose – The debate about services-led competitive strategies continues to grow, with much interest emerging around the differing practices between production and servitized operations. The purpose of this paper is to contribute to this discussion by investigating the vertical integration practice (in particular the micro-vertical integration, otherwise known as the supply chain position) of manufacturers who are successful in their adoption of servitization. Design/methodology/approach – To achieve this the authors have investigated a cross-section of four companies which are successfully delivering advanced services coupled to their products. Findings – Manufacturers who have embraced the servitization trend tend to retain capabilities in design and production, and do so because this benefits their speed, effectiveness and costs of supporting assets on advanced services contracts. Research limitations/implications – These are preliminary findings from a longer term research programme. Practical implications – Through this research note the authors seek to simultaneously contribute to the debate in the research community and offer guidance to practitioners exploring the consequences of servitization. Originality/value – Successful servitization demands that manufacturers adopt new and alternative practices and technologies to those traditionally associated with production operations. A prevailing challenge is to understand these differences and their underpinning rationale. Therefore, in this research note, the authors report on the practices of four case companies, explore the rationale underpinning these, and propose an hypothesis for the impact on vertical integration of successful servitization.

Longitudinal dispersion in spiral wound RO modules and its effect on the performance of batch mode RO operations

Operation of reverse osmosis (RO) in cyclic batch mode can in principle provide both high energy efficiency and high recovery. However, one factor that causes the performance to be less than ideal is longitudinal dispersion in the RO module. At the end of the batch pressurisation phase it is necessary to purge and then refill the module. During the purge and refill phases, dispersion causes undesirable mixing of concentrated brine with less concentrated feed water, therefore increasing the salt concentration and energy usage in the subsequent pressurisation phase of the cycle. In this study, we quantify the significance of dispersion through theory and experiment. We provide an analysis that relates the energy efficiency of the batch operation to the amount of dispersion. With the help of a model based on the analysis by Taylor, dispersion is quantified according to flow rate. The model is confirmed by experiments with two types of proprietary spiral wound RO modules, using sodium chloride (NaCl) solutions of concentration 1000 to 20,000 ppm. In practice the typical energy usage increases by 4% to 5.5% compared to the ideal case of zero dispersion.